The present disclosure generally to a two-wheeled vehicle and more particularly, but not exclusively, the present disclosure relates to an exhaust system of the vehicle.
BACKGROUND
[002] The information in this section merely provides background information related to the present disclosure and may not constitute prior art(s) for the present disclosure.
[003] In the 21st century environment is taking a huge hit due to air pollution and one of the major causes of concern is the carbon monoxide produced by transport vehicles such as ships, airplanes, and road vehicles. Exhaust emissions from vehicles is one of the main sources of air pollution. The data from different governing bodies says that air pollution from motor vehicles, especially premium fuel (spark ignition engines) is 70% of carbon monoxide (CO) and 60% of hydrocarbon (HC). Gas emissions of carbon monoxide and hydrocarbon are toxic and harmful to the environment and human health. The exhaust gases from a two-wheeler engine, or any other petrol vehicle, contain majorly three toxic gases i.e. Oxides of nitrogen (NOx), Hydrocarbons (HC), and Carbon Monoxide (CO). Further, the internal combustion engine is the chief source of production of carbon monoxide.
[004] Combustion products from IC engine are released into the atmosphere which contains harmful compounds such as oxides of nitrogen, hydrocarbons, carbon monoxide, particulate matter and other pollutants. Different regulatory bodies regulate emission standards for automobile which quantitatively limits the permissible amount of specific air pollutants which are released to atmosphere. One of the important steps taken by the regulatory authorities is to regulate the emission control and different emission control techniques are used to control emissions in IC engine vehicles. Some of the known techniques are three-way and two-way catalyst technology which are currently being used to reduce emissions from automotive vehicle. The IC engine vehicles are generally mounted with exhaust system to discharge by-products of combustion and waste gases to the atmosphere.

[005] The most effective technology to reduce emissions of Carbon Monoxide (CO) and Hydrocarbon (HC) is the application of a catalytic converter (cat-con) in the exhaust system of the vehicle. The function of a catalytic converter is oxidizing of carbon monoxide and hydrocarbon emissions quickly. The aim of catalytic converter installation in the exhaust system of motorcycle muffler is to convert harmful pollutants such as carbon monoxide and hydrocarbon into harmless gases such as carbon dioxide (C02) and water vapor (H20) through a chemical reaction as shown in equation (1) for carbon monoxide and equation (2) for hydrocarbon.
2CO + 02^2C02 (1)
HC + 02 -> C02 + H20 (2)
[006] The catalytic converter combines oxygen with carbon monoxide to form non-poisonous carbon dioxide reducing the high concentrations in the exhaust manifold to low concentrations. The catalytic converter is basically an exhaust control device that is located between the engine and the exhaust pipe/muffler. The purpose of catalytic converter is to reduce the volume of toxic gases (CO, NOX, HC) coming from the engine by converting them into less harmful pollutants (C02, Nitrogen, Oxygen, and water or steam) before they get released out in the atmosphere. The catalytic converter uses a chamber called a catalyst to change the harmful compounds from an engine's emissions into less harmful gases.
[007] The catalytic converter works to split up the unsafe molecules in the gases that an engine produces before they get released into the atmosphere. The gases are brought into the catalytic converter from the input tube connected to the engine of a vehicle. The exhaust gases are blown over the catalyst, which causes a chemical reaction that breaks apart the pollutants and the less-harmful gases now travel through the second tube, or the "output," that is connected to tailpipe of the vehicle. This is basically done by a series of chemical reactions using catalysts, which are usually elements like platinum, rhodium, and palladium. These catalysts are coated on a honeycomb structure inside the catcon. The exhaust gases coming out from the engine pass through the vents of the said honeycomb structure and two chemical reactions take place oxidation (adding oxygen, as in from CO to C02 or HC to H20) and Reduction (removing

oxygen, like NO to N2). The role of the catalysts is to simply accelerate the rate of these two chemical reactions.
[008] The catalyst present in the catalytic converter requires minimum or optimum temperature in order to activate and covert the harmful gases into less harmful gases. Therefore, they are required to be placed closer to the engine. The temperature of exhaust gases reduces with the increase in distance from the exhaust port. Another important factor is the time to reach light off temperature to activate cat-con to start work. As soon as required temperature is achieved in cat-con it starts working efficiently.
[009] For the effective working of the catalytic converter, pressure plays an important factor as the excessive pressure loss of exhaust muffler causes a decrease in engine power so as to increase the fuel consumption of vehicle. Also, the engine performance is dependent on exhaust system pressure drop. The geometry of exhaust system creates an undesirable back pressure which can affect engine parameters such as decrease in power, increased fuel consumption etc. Higher pressure loss is generated inside the exhaust system due to vortex and at the same time, the vortex is the may cause of noise production.
[010] The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the prior art.
SUMMARY
[011] The one or more shortcomings of the prior art are overcome by the system/assembly as claimed, and additional advantages are provided through the provision of the system/assembly/method as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

[012] In accordance with an aspect of the present disclosure, an exhaust system of an engine of a vehicle is disclosed. The exhaust system comprises a first section fluidically coupled with an exhaust port of the engine. The first section is defined with a profile having a radius of curvature. A second section, wherein at least a portion of the second section defined with an inclined portion and a substantially horizontal portion. An exhaust after treatment unit inclinedly positioned between the first section and the second section.
[013] In an embodiment, a neutral axis of the first section extends along and into a central axis of the exhaust after treatment unit.
[014] In an embodiment, the radius of curvature of the first section ranges from 45 mm to 250 mm.
[015] In an embodiment, an imaginary axis extending from a plane of an inlet of the first section and an imaginary axis extending from a plane of an outlet of the first section intersect at point forming an obtuse angle.
[016] In an embodiment, the imaginary axis extending from a plane of an inlet of the first section and an imaginary axis extending from a plane of an outlet of the first section intersect at point forming an included angle ranging from 95 degrees to 130 degrees .
[017] In an embodiment, the exhaust after treatment unit is a catalytic convertor.
[018] In an embodiment, the profile of the first section is configured to provide a uniform flow of exhaust gases from the exhaust port into the exhaust after treatment unit.
[019] In an embodiment, the exhaust port is positioned tangential with the first section of the exhaust system and is configured to ensure minimum pressure drop. Thus, exhaust gas stream released from engine, travels in a substantial tangential path ensuring minimal drop in pressure drop.

[020] In an embodiment, the inlet of the first section is coupled with the exhaust port and the outlet of the first section is fluidly connected to an inlet side of the exhaust after treatment unit.
[021] In an embodiment, the second section comprises an inlet fluidly connected to an outlet side of the exhaust after treatment unit.
[022] In an embodiment, the second section defined with the inclined portion and the substantially horizontal portion is coupled with a muffler of the vehicle.
[023] In an embodiment, an oxygen sensor positioned proximate to the outlet of the first section.
[024] In an embodiment, an exhaust manifold connects the inlet of first section with exhaust port.
[025] In an embodiment, the outlet of the first section is located in front than the inlet of the first section when the vehicle is viewed in side view.
[026] In accordance with another aspect of the present disclosure, a vehicle comprises a main frame, an internal combustion engine mounted on the main frame through the engine mounting system. An exhaust system, the exhaust system comprising a first section fluidically coupled with an exhaust port of the engine, the first section is defined with a profile having a radius of curvature. A second section, wherein at least a portion of the second section defined with an inclined portion and a substantially horizontal portion. An exhaust after treatment unit inclinedly positioned between the first section and the second section.
[027] An exhaust system of an engine of a vehicle for discharging the exhaust gas from the engine is disclosed in accordance with an embodiment of the present disclosure. The exhaust system comprises a first section fluidically coupled with an exhaust port of the engine. The first section is defined with a profile having a radius of curvature. A second section, wherein at least a portion of the second section defined

with an inclined portion and a substantially horizontal portion. An exhaust after treatment unit inclinedly positioned between the first section and the second section. This ensures lesser pressure drop in the exhaust system and conversion efficiency is improved. The pressure drop is lesser and up to a range of 2% to 5 % by keeping the catalytic converter at end of a single curved tube connecting exhaust port with catalytic converter. The lesser pressure drop in exhaust system is helpful for improved vehicle performance e.g., higher torque and lower fuel consumption. This helps in reducing exhaust noise generation.
[028] Generally, high-density catalytic converter is desired as the conversion efficiency of the high-density catalytic converter is higher thereby enhance the conversion of harmful gases into less hazardous to the environment, but the high-density catalytic converter also offer the higher pressure drop. The higher density catalytic converter may also create a high back pressure for engine that may negatively affect the working efficiency of the engine which is undesirable. .As disclosed in the above paragraphs, the first section is having a single arc profile with no bends or sharp edges. Due to the single arc profile , the pressure drop is reduced which effects the flow and eventually to the pressure drop. Thus, in the present disclosure, low pressure drop is achieved due to presence of circular profile. Due to the low pressure drop in the exhaust system, a high density of catalytic converter may be used. In the embodiment of the present disclosure, the drop in the overall pressure provide flexibility in choosing the catalytic converter of suitable or higher density. Thus, the curved or circular pipe leads to low pressure drop, the low pressure drop eventually leads in selecting a higher density catalytic converter.
[029] Single curved exhaust tube is cost effective over multiband tubes due to less time consumed in operations and overall productivity improves significantly. Also, curved tubes have advantage over welded halves in terms of strength and less weight in nature. Low weight parts with good strength are better solution to improve vehicle performance. Reduced weight benefits all areas of vehicle handling and performance. This provides overall comfort to rider by keeping noise at low levels. The present disclosure provides compact arrangement of exhaust system in a two-wheeler vehicle. The compact size of exhaust system provides advantage to designer to arrange exhaust system as per rider comfort and utilizing maximum benefits.

[030] In an embodiment of the present disclosure, the exhaust system comprises an oxygen sensor which is positioned proximate to the outlet of the first section. The oxygen sensor monitors the amount of oxygen and provide feedback to a fuel injection system to increase or decrease the amount of oxygen used in the fuel/air mixture used to power the engine. Generally, the oxygen sensor is required to be positioned near to the exhaust port. However, due to high temperature of the exhaust gases, there was problem of burning of the oxygen sensor in the prior art. In the present embodiment due to uniform flow of the exhaust gases, the oxygen senor may be positioned slightly way from the exhaust port and also enables easy serving of the oxygen sensor.
[031] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.
[032] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF FIGURES
[033] The novel features and characteristics of the disclosure are set forth in the description. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:
[034] Figure 1 illustrates a side view of a vehicle, in accordance with an embodiment of the present disclosure.
[035] Figure 2 illustrates a top view of the vehicle of Figure 1.

[036] Figure 3 illustrates a view of a two-wheeler vehicle illustrating exhaust system in accordance with the embodiment of the present disclosure.
[037] Figure 4 illustrates another view of a two-wheeler vehicle illustrating exhaust system in accordance with the embodiment of the present disclosure.
[038] Figure 5 is illustrates a view of exhaust system in accordance with the embodiment of the present disclosure.
[039] Figure 6 illustrates another view of exhaust system illustrating imaginary axes XX and YY and their intersecting angle in accordance with the embodiment of the present disclosure.
[040] Figure 7 is a view of exhaust seat, exhaust valve and exhaust system in accordance with the embodiment of the present disclosure.
[041] Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of embodiments of the present disclosure.
DETAILED DESCRIPTION
[042] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the FIGS, and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure as defined by the appended claims.
[043] Before describing detailed embodiments, it may be observed that the novelty and inventive step that are in accordance with the present disclosure resides in an exhaust system of an engine of a vehicle It is to be noted that a person skilled in the art can be motivated from the present disclosure and modify the various constructions of

exhaust system of an engine of a vehicle. However, such modification should be construed within the scope of the present disclosure. Accordingly, the drawings are showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
[044] In the present disclosure, the term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
[045] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusions, such that a device that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such setup or device. In other words, one or more elements in a system or apparatus proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
[046] The terms like "at least one" and "one or more" may be used interchangeably or in combination throughout the description.
[047] While the present disclosure is illustrated in the context of a vehicle, however, exhaust system of an engine of a vehicle thereof can be used with other type of vehicles as well. The terms "modular vehicle", "vehicle", "two-wheeled vehicle", "electric vehicle", "EV" and "motorcycle" have been interchangeably used throughout the description. The term "vehicle" comprises vehicles such as motorcycles, scooters, bicycles, mopeds, scooter type vehicle, and the like.
[048] The terms "front/forward", "rear/rearward/back/backward", "up/upper/top", "down/lower/lower ward/downward, bottom", "left/leftward", "right/rightward" used therein represents the directions as seen from a vehicle driver sitting astride.

[049] Reference will now be made to the exemplary embodiments of the disclosure, as illustrated in the accompanying drawings. Wherever possible, same numerals will be used to refer to the same or like parts. Embodiments of the disclosure are described in the following paragraphs with reference to FIGS. 1 to 4. In FIGS. 1 to 6, the same element or elements which have same functions are indicated by the same reference signs.
[050] Referring to FIG. 1 and FIG. 2, an exemplary vehicle (100) according to an embodiment of the present disclosure is depicted. The vehicle (100) referred to herein, embodies an off-road two-wheeler vehicle, comprising an Internal Combustion engine (hereinafter referred to as "engine") for generating power to drive the vehicle. Alternatively, the vehicle may embody any other ridden vehicle such as electric motorcycle, a tri-cycle, scooters and likewise, without limiting the scope of the invention.
[051] Referring to FIG. 1 and FIG. 2, the vehicle (100) comprises a front body structure (101) and a rear body structure (102). The front body structure (101) extending from a first end of the vehicle up to a seat (103) of the vehicle (100) along a longitudinal plane and the rear body structure (102) extending from the seat (103) to a rear end of the vehicle (100). The front body structure (101) comprises a front road engaging member, illustratively a front wheel (104), a plurality of front shock absorbers (105), a front wheel brake mechanism (106), a steering mechanism (107), a dash assembly (108), a head lamp unit (109) and a plurality of front winkers (110). The plurality of front shock absorbers (105) are coupled to the front wheel (104) to absorb shocks and/or jerks exerted on the front wheel (104) of the vehicle (100), during operating condition of the vehicle (100). The operating condition of the vehicle (100) may be defined as a condition when the vehicle (100) is in motion. A head pipe (111) pivotably coupled to one end of the plurality of front shock absorbers (105). The front shock absorbers (105) may comprise of spring dampers, but not limited to the same.
[052] Alternatively, the front shock absorbers (105) may comprise of hydraulic or oil dampers to efficiently absorb shocks and/or jerks exerted on the front wheel (104) of the vehicle (100). An assembly comprising mounting of the plurality of front shock

absorbers (105) to the front wheel (104), may be defined as a front suspension assembly of the vehicle (100). The front wheel (104) is fitted with the front wheel brake mechanism (106) for application of brakes onto the front wheel (104) of the vehicle (100), to facilitate stopping of the vehicle (100). The front wheel brake mechanism (106) may comprise of drum brake mechanism, but not limited to the same. Alternatively, a disc brake mechanism may also be employed to the front wheel brake mechanism (106) of the vehicle (100). According to another embodiment of the present disclosure, the steering mechanism (107) comprises a handlebar (107a) and the handle bar (107a) is configured to be mounted on the head pipe (111) of the vehicle (100).
[053] In the illustrated example, the dash assembly (108) is provided on the handle bar (107a) of the steering mechanism (107). The dash assembly (108) comprises a display unit (108a). The display unit (108a) displays information relating to the vehicle (100) to the operator. The display unit (108a) may comprise of a display screen, preferably an LCD screen but not limited to the same. Alternatively, the dash assembly (108) may comprise additional components such as GPS, Graphic User Interface (GUI), fuel gauge etc, without limiting scope of the invention. In the illustrated example, the head lamp unit (109) is provided on the steering mechanism (107).
[054] In an exemplary embodiment of the present disclosure, a fuel tank (112) is mounted on the front body structure (101) of the vehicle (100). The fuel tank (112) is positioned between the handlebar (107a) and the seat (103) of the vehicle (100), as shown in FIG. 2. The fuel tank (112) is connected to a main frame (113) of the vehicle (100) by means of fasteners. Alternatively, the fuel tank (112) may be attached to the main frame (113) by other attachment means for example - welding, etc. The fuel tank (112) is adapted to receive fuel of the vehicle (100). The front body structure (101) comprises an at least one stand (114) mount on the main frame (113) of the vehicle (100).
[055] In an illustrated example, the rear body structure (102) comprises the seat (103), a rear grounding engaging member, illustratively a rear wheel (115), a muffler (116), a rear wheel guard (116a) and a rear fender (117). The rear wheel (115) is positioned in line with the front wheel (104) along the longitudinal plane of the vehicle (100). The main frame (113) is supported by the front wheel (104) and the rear wheel (115). The

main frame (113) is defined having a front portion (113a), a center portion (113b) and a rear portion (113 c). The front portion (113 a) of the main frame (113) is configured to provide provisions for mounting a radiator (118) and an engine (119). Alternatively, the main frame (113) mays also provides provisions for mounting other peripheral components of the vehicle (100), for example-carburettor, fuel injector, battery, etc, without limiting scope of the invention. The center portion (113b) of the main frame (113) provides provision for mounting the engine (119), an exhaust system (200) and the silencer or muffler (116) of the vehicle (100). The center portion (113b) of the main frame (113) also provides support to the fuel tank (112) of the vehicle (100). The rear portion (113c) of the main frame (113) provides support to the seat (103) of the vehicle (100).
[056] In an embodiment of the present disclosure, as the combustion of mixture of fuel and air takes place inside the engine, the fumes and exhaust gases are generated and are discharged through the exhaust system to the environment. The exhaust system collects the exhaust gases from the cylinders, removes harmful substances, reduces the level of noise and discharges the purified exhaust gases to the atmosphere. The exhaust system of the vehicle is designed to take care of toxic emissions automobiles produces. It directs harmful hydrocarbons away from the driver and passengers and reduce the air pollutants automobiles releases into the environment, helping keep the air clean. The exhaust system also significantly reduces the amount of noise the vehicle produces, keeps the vehicle sound pleasant as it runs and reduces noxious gases. Referring to figure 3, the vehicle (100) may comprise an exhaust system (200) with an exhaust port (202) located proximate to the engine bracket. The engine (119) may include an engine cylinder head (120) and a cylinder head port (121) .
[057] As shown in Figure 3-6, the exhaust system (200) comprises a first section (201) which is fluidically coupled with an exhaust port (202) of the engine. The exhaust gases from the exhaust port (202) travels to an exhaust manifold (214) and the exhaust manifold (214) connects with the first section (201). The first section (201) of the exhaust system (200) may comprise an inlet (209) and an outlet (210). In an embodiment of the present disclosure, the exhaust manifold (214) connects the inlet (209) of first section (201) with exhaust port (202) . As illustrated in figure 4 and 5, the

first section (201) is defined with a profile having a radius of curvature. The value radius of curvature lies in the range of 45 mm to 250 mm.
[058] In the embodiment of the present disclosure, the first section (201) is having a single arc profile in such a manner that no bends or sharp ends are formed in the first section (201) of the exhaust system (200). The outlet of the first section (201) is configured with an exhaust after treatment unit (206).
[059] In an embodiment of the present disclosure, the exhaust after treatment unit (206) is the unit which reducing the harmful exhaust emissions from internal-combustion engines and cleans exhaust gases to ensure the engines meet emission regulations. In an embodiment of the present disclosure, the exhaust after treatment unit (206) is a catalytic converter . In the present disclosure the exhaust after treatment unit (206) is interchangeably used as the catalytic converter (206).
[060] The exhaust after treatment unit (206) may comprise an inlet (211) and an outlet (213). The inlet (211) of the exhaust after treatment unit (206) is connected with the outlet (210) of the first section (201) and the outlet (213) of the exhaust after treatment unit (206) is coupled with a second section (204) in such a manner that the exhaust after treatment unit (206) is inclinedly positioned between the first section (201) and the second section (204).
[061] In the embodiment of present disclosure, the second section (204) may comprise an inlet (212)and an outlet (216). The inlet (212) of the second section (204) is fluidly connected to the outlet (213) of the exhaust after treatment unit (206). The outlet (216) of the second portion is defined with portions wherein at least a portion of the outlet is defined with an inclined portion and a substantially horizontal portion (205). The substantially horizontal portion (205) of the second portion (204) is coupled with a muffler (116) of the vehicle (100).
[062] In an embodiment of the present disclosure and as disclosed in above paragraphs, the first section (201) is having a circular profile with the radius of curvature in the range of 45 mm to 250mm. The circular profile is having a neutral axis
(207).

[063] In an embodiment of the present disclosure, the first section (201) is a pipe having a circular profile, however in the present disclosure, it is not limited only to only pipe and may have any other suitable geometry. In an embodiment of the present disclosure the pipe is having a single arc profile. In an alternate embodiment of the present disclosure the pipe is having a profile of a continuous arc with contact thickness. In yet another embodiment of the present disclosure, the pipe is having a profile of an elliptical arc. The first section (201) from the inlet (209) to the outlet (210) is having a circular profile and runs along the neutral axis (207). In the embodiment of the present disclosure, the neutral axis (207) of the first section (201) extends along and into a central axis (208) of the exhaust after treatment unit (206).
[064] The term "extends along and into" defines that the neutral axis (207) of the first section (201) transitions or shifts to the central axis (208) of the exhaust after treatment unit (206). The term "central axis of the exhaust after treatment unit" is defined as an imaginary axis which runs along the unit and through the midpoint of its diameter. In the embodiment of the present disclosure, the exhaust after treatment unit (206) is having a cylindrical shape however, in the present disclosure, it is not limited only to cylindrical shape and may have any other suitable geometry.
[065] In an embodiment of the present disclosure and as illustrated in figure 5, an imaginary axis (X-X) extends from a plane of an inlet (209) of the first section (201) in the side view, as shown. Also, another imaginary axis (Y-Y) extends from a plane of an outlet (210) of the first section (201) in the side view, as shown. In an embodiment of the present disclosure, the imaginary axis (X-X) intersects with the the imaginary axis (Y-Y) at a point forming an obtuse angle. In an alternate embodiment of the present disclose the intersection of both the axis (X-X) and (Y-Y) forms an included angle which range from 95 degrees to 110 degrees.
[066] In an embodiment of the present disclosure, the exhaust after treatment unit (206) or the catalytic converter reduces the harmful emissions. The catalytic converter comprise a catalyst that converts harmful emissions into safe emissions. The rare metal such as are platinum (Pt), palladium (Pd), and rhodium (Rh) are present and act as catalysts, both as a reduction catalyst (Pt and Rh) and as an oxidation catalyst (Pt and

Pd). The reduction catalyst removes oxygen from the nitrogen oxides to release it as mild nitrogen. The oxidation catalyst uses free oxygen to bind to carbon monoxide (CO) to obtain carbon dioxide (CO). In addition, the oxidation catalyst oxidizes any burned hydrocarbons as well into molecules of carbon dioxide and water. As a result, the harmful gases (CO, NOx and unburden fuel) are converted into safer gases (C02, N2, H20) in the catalytic converter. The final emissions from the vehicle are safer because harmful emissions are reduced by the converter.
[067] The effectiveness or the conversion efficiency of the catalytic converter (206) basically depends on the uniformity of flow and the overall pressure drop. For the effective working of the catalytic converter pressure plays an important factor as the excessive pressure loss in the exhaust system (200) causes a decrease in engine power so as to increase the fuel consumption of vehicle. Thus, an exhaust system with low pressure loss is a necessity for effective exhaust system. Also, exhaust system pressure drop is one of the factors which governs the engine performance
[068] The "overall pressure drop" is defined as the difference of pressure between the exhaust port (202) of engine and tail pipe (122). In other words, the overall pressure drop is a difference in the value of pressure from the inlet (209) of the first section (201) and the atmosphere (as the pressure of exhaust of muffler is the atmospheric pressure).
[069] Generally, high-density catalytic converter (206) is desired as the conversion efficiency of the high-density catalytic converter (206) is higher thereby enhance the conversion of harmful gases into less hazardous to the environment, but the high-density catalytic converter (206) also offer the higher pressure drop. The higher density catalytic converter (206) may also create a high back pressure for engine (119) that may negatively affect the working efficiency of the engine (119), which is undesirable. .As disclosed in the above paragraphs, the first section (201) is having a single arc with no bends or sharp edges. Due to the circular profile, the pressure drop is reduced which effects the flow and eventually to the pressure drop. Thus, in the present disclosure, low pressure drop is achieved due to presence of circular profile. Due to the low pressure drop in the exhaust system, a high density of catalytic converter (206) may be used.

[070] In the embodiment of the present disclosure, the drop in the overall pressure provide flexibility in choosing the catalytic convertor (206) of suitable or higher density. Thus, the curved or circular pipe leads to low pressure drop, the low pressure drop eventually leads in selecting a higher density catalytic convertor (206).
[071] The turbulence in the flow of exhaust gas may also affect the overall performance of the catalytic convertor. Higher pressure loss is generated inside the exhaust system due to turbulence and at the same time, the turbulence is the main cause of noise. The turbulence may be minimized by keeping routings of the exhaust system with minimum bends and substantial tangent tube routing.
[072] In the present disclosure, the formation of low turbulence is achieved by the single arc profile of the first section (201) as the flow from the exhaust manifold (214) is uniform and constant due to presence of single arc profile and absence of bends. The exhaust gas discharge into the face of the catalytic convertor (206) uniformly due to low turbulence which is formed due to single arc profile of first section. In the known art, bends were present in the piping layout which makes the flow turbulent and decreases the conversion efficiency of the catalytic convertor. The presence of single arc profile of first section (201) leads to the decrease in the turbulence. The placement of the catalytic convertor (206) closer to exhaust port (202) plays significant role in performance of exhaust system and vehicle efficiency and in the present disclosure the catalytic convertor (206) is located proximate to the exhaust port (202) .
[073] In an embodiment of presnet disclosure, the catalytic convertor (206) is positioned in front portion of vehicle engine (119) and in inclined position such that it connects the first section (201) wth the second section (204 ). The first section (201) is designed in such a way that its pipe routing go in front of vehicle engine (119) and then it is routed in backward direction in vehicle (100) when vehicle seen in the side view.
[074] In an embodiment of the present disclosure, the catalytic convertor (206) is placed in advantageous position and below the outlet (210) of first section (201) when vehicle (100) seen in the side view. The single arc profile of the first section (201) enables the exhaust system (200) layout to place catalytic convertor (206) away from the front wheel (104). Therefore, life of front wheel (104) and front fender increases

due to less heat radiation from the exhaust system (200) towards the front wheel (104) and front fender. In addition, such arrangement of the first section (201) is advantageous and pressure drop of exhaust system improves from 8% to 3%.
[075] Due to this exhaust system (200) layout arrangement, the catalytic converter (206) is positioned closer to cylinder head port (120) and after single first section. Due to placement of catalytic converter (206) near to exhaust port (202), it provide better light off temperature and the temperature reaching catalytic converter (206) is optimum to activate the catalytic converter (206) and work at better efficiency rate.
[076] In an embodiment of the present disclosure, the first section (201) is positioned behind front wheel 104 in such a manner that it is less exposed to direct air flow when vehicle (100) is moving in front direction. Hence, more than 60% area of first section (201) is not exposed to direct air flow in vehicle layout. Due to less exposure with hot first section (201), surrounding air temperature rise is minimised and low surrounding air temperature provides comfort to rider as higher temperature at rider leg reduces comfort.
[077] In an embodiment of the present disclosure the first section (201) is substantially tangential with cylinder head port (121) and catalytic converter (206) . As illusatred in figure 6 which is an enlarged view of exhaust port (202) and exhaust system (200) according to embodiment of the present disclosure. An exhaust valve (217) rests on exhaust seat (218) and the axis of exhaust valve (217) is coaxial with the axis of exhaust seat (218) A cylinder head port axis (219) is substantially tangential with the exhaust valve axis (220) which is further substantially tangential with neutral axis (207) of the first section (201). This ensures smooth exhaust gas discharge from engine.
[078] In an embodiment of the present disclosure, the exhaust system (200) comprises an oxygen sensor which is positioned proximate to the outlet (210) of the first section (201). The oxygen sensor monitors the amount of oxygen and provide feedback to the a fuel injection system to increase or decrease the amount of oxygen used in the fuel/air mixture used to power the engine (119). Generally, the oxygen sensor is required to be positioned near to the exhaust port. However, due to high temperature of the exhaust gases, there was problem of burning of the oxygen sensor in the prior art. In the present embodiment due to uniform flow of the exhaust gases, the oxygen sensor may be

positioned slightly way from the exhaust port and also enables easy serving of the oxygen sensor.
[079] The various embodiments of the present disclosure have been described above with reference to the accompanying drawings. The present disclosure is not limited to the illustrated embodiments; rather, these embodiments are intended to fully and completely disclose the subject matter of the disclosure to those skilled in this art. In the drawings, like numbers refer to like elements throughout. Thicknesses and dimensions of some components may be exaggerated for clarity.
[080] Herein, the terms "attached", "connected", "interconnected", "contacting", "mounted", "coupled" and the like can mean either direct or indirect attachment or contact between elements, unless stated otherwise.
[081] Well-known functions or constructions may not be described in detail for brevity and/or clarity. As used herein the expression "and/or" includes any and all combinations of one or more of the associated listed items.
[082] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and/or "including" when used in this specification, specify the presence of stated features, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, operations, elements, components, and/or groups thereof.
[083] While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing

descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
EQUIVALENTS:
[084] The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[085] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
[086] Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application. [087] The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

WE CLAIM:

1. An exhaust system (200) of an engine (119) of a vehicle (100), the exhaust system
(200) comprising:
a first section (201) fluidically coupled with an exhaust port ( 202) of the engine (119), the first section (201) is defined with a profile (203) having a radius of curvature;
a second section (204), wherein at least a portion of the second section defined with an inclined portion and a substantially horizontal portion (205);
an exhaust after treatment unit (206) inclinedly positioned between the first section (201) and the second section (204).
2. The exhaust system (200) as claimed in claim 1 wherein a neutral axis (207) of the first section (201) extends along and into a central axis (208) of the exhaust after treatment unit (206).
3. The exhaust system as claimed in claim 1 wherein the radius of curvature of the first section (201) ranges from 45 mm to 250 mm
4. The exhaust system as claimed in claim 1 wherein an imaginary axis (X-X) extending from a plane of an inlet (209) of the first section (201) and an imaginary axis (Y-Y) extending from a plane of an outlet (210) of the first section (201) intersect at point forming an obtuse angle.

5. The exhaust system as claimed in claim 4 wherein the imaginary axis (X-X) extending from a plane of an inlet (209) of the first section (201) and an imaginary axis (Y-Y) extending from a plane of an outlet (210) of the first section intersect (201) at point forming an included angle ranging from 95 degrees to 110 degrees.
6. The exhaust system as claimed in claim 1 wherein the exhaust after treatment unit (206) is a catalytic convertor.
7. The exhaust system as claimed in claim 1 wherein the profile of the first section (201) is configured to provide a uniform flow of exhaust gases from the exhaust port (202) into the exhaust after treatment unit (206).

8. The exhaust system as claimed in claim 1 wherein the exhaust port (202) is positioned tangential with the first section (201) of the exhaust system (200) and is configured to ensure minimum pressure drop.
9. The exhaust system as claimed in claim 1 wherein the inlet (209) of the first section (201) is coupled with the exhaust port (202) and the outlet (210) of the first section (201) is fiuidly connected to an inlet (211) of the exhaust after treatment unit (206).
10. The exhaust system as claimed in claim 1 wherein the second section (204)
comprises an inlet (212) fiuidly connected to an outlet (213) of the exhaust after
treatment unit (206).
11. The exhaust system as claimed in claim 1 wherein the second section (204) defined with the inclined portion and the substantially horizontal portion (205) is coupled with a muffler of the vehicle(lOO).
12. The exhaust system as claimed in claim 1 comprises an oxygen sensor positioned proximate to the outlet (210) of the first section (201).
13. The exhaust system as claimed in claim 1 wherein an exhaust manifold (214) connects the inlet (209) of first section (201) with exhaust port (202).
14. The exhaust system as claimed in claim 1 wherein the outlet (210) of the first section (201) is located in front than the inlet (209) of the first section (201) when the vehicle is viewed in side view.
15. A vehicle (100) comprising: a main frame (113);
an internal combustion engine (119)mounted on the main frame (113) through the
engine mounting system;
an exhaust system, the exhaust system (200) comprising:
a first section (201) fluidically coupled with an exhaust port ( 202) of the engine (119), the first section (201) is defined with a profile (203) having a radius of curvature;

a second section (204), wherein at least a portion of the second section defined with an inclined portion and a substantially horizontal portion (205);
an exhaust after (206) treatment unit inclinedly positioned between the first section (201) and the second section (204).