FORM 2
THE PATENTS ACT, 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10; rule 13]
TITLE: “A TEST APPARATUS FOR MEASURING ACOUSTICS OF AN
EXHAUST SYSTEM”
NAME AND ADDRESS OF THE APPLICANT:
TATA MOTORS PASSENGER VEHICLES LIMITED of Floor 3, 4, Plot-18, Nanavati
Mahalaya, Mudhana Shetty Marg, BSE, Fort, Mumbai, Mumbai City, Maharashtra, 400001
India
Nationality: Indian
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
[001] Present disclosure relates to a field of automobiles. Particularly, but not exclusively, the present disclosure relates to measurement of acoustics of an exhaust system. Further, embodiments of the present disclosure disclose a test apparatus for measuring acoustics of the exhaust system.
BACKGROUND OF THE DISCLOSURE
[002] Generally, vehicles upon manufacturing need to comply various standards, for instance, Indian Standards (IS), Automotive Industry standards (AIS), etc. before entering into the market. Such IS/AIS comprises emission standards, Noise, Vibration, and Harshness (NVH) standards, and among others. In convention, NVH characteristics of the vehicle are measured once the complete vehicle is developed. This vehicle is not available to public and is solely limited for testing purposes. However, once the complete vehicle is manufactured, NVH characteristics are measured to check the compliance with the IS/AIS standards. If the measured NVH characteristics are not meeting the requirements of the said IS/AIS standards, the manufacturer needs to re-develop the entire vehicle, especially engine and exhaust related components. This process of manufacturing the vehicle and re-developing is carried out repeatedly until the required standards are met. This process increases development time of the vehicle. Also, such process to meet the standard requirement necessitates enormous cost and effort.
[003] Therefore, there is a need of a test rig which is capable of measuring NVH characteristics of the engine and exhaust components before fitting into the vehicle. The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the aspect of measuring acoustics of the exhaust.
[004] The drawbacks/difficulties/disadvantages/limitations of the conventional techniques explained in the background section are just for exemplary purpose and the disclosure would never limit its scope only such limitations. A person skilled in the art would understand that this disclosure and below mentioned description may also solve other problems or overcome the other drawbacks/disadvantages of the conventional arts which are not explicitly captured above.

SUMMARY OF THE DISCLOSURE
[005] One or more shortcomings of the conventional exhaust measurement are overcome by a test apparatus for measuring acoustics of an exhaust, as described. 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.
[006] In a non-limiting embodiment of the disclosure a test apparatus for measuring acoustics of an exhaust system is disclosed. The apparatus comprises a first chamber removably connected to a blower. The blower is configured to draw air from the surroundings and blow the drawn air into the first chamber at a predetermined speed. The first chamber is configured to heat the air to a predetermined temperature. The apparatus further comprises a second chamber, fluidly connected to the first chamber. The second chamber comprises a rotor and a stator. A first end of the second chamber receives the heated air from the first chamber. Furthermore, the apparatus comprises an outlet coupled to a second end of the second chamber for passage of the exhaust air from the second chamber. Rotation of the rotor on the stator exhausts the air from the second chamber in a pulsating manner to the outlet, to measure acoustics of the exhaust at the outlet.
[007] In an embodiment, the apparatus comprises a motor coupled to the rotor and is configured to rotate the rotor.
[008] In an embodiment, the rotor is defined with a 25% opening and the stator is defined with a 50% opening to generate exhaust pulses of a second order.
[009] In an embodiment, the apparatus comprises a conduit disposed between the first chamber and the first end of the second chamber for the passage of the heated air.
[0010] In an embodiment, the first chamber comprises a heating coil adapted to heat the air to the predetermined temperature to mimic the temperature of the exhaust system in real time.
[0011] In an embodiment, the apparatus comprises a first valve coupled to the blower, the first valve is configured to drain the excess air from the blower.
[0012] In an embodiment, the apparatus comprises a second valve coupled to the first chamber, the second valve is configured to drain the excess heated air from the first chamber.

[0013] In an embodiment, the apparatus comprises a third valve coupled to the conduit, the third valve is configured to drain the excess heated air accumulated in the second chamber.
[0014] In an embodiment, the apparatus comprises a sensor coupled to the conduit, the sensor is configured to measure the temperature of the heated air in the conduit.
[0015] In an embodiment, the apparatus comprises a pulley arrangement to transfer the rotational movement of the motor to the rotor.
[0016] In an embodiment, the pulley arrangement comprises a driver pulley, a driven pulley, and a driving component.
[0017] In an embodiment, the driving component is one of a belt and a chain.
[0018] In an embodiment, a method for measuring acoustics of an exhaust is disclosed. The method comprises drawing air from the surrounding by a blower. Further, the method comprises supplying the air from the blower to a first chamber. Furthermore, the method comprises heating the air in the first chamber to a predetermined temperature. In addition, the method comprises supplying the heated air from the first chamber to a second chamber. Also, the method comprises rotating a rotor on a stator to exhaust the air from the second chamber in a pulsating manner to an outlet. Moreover, the method comprises measuring acoustics of the exhaust at the outlet.
[0019] 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 THE ACCOMPANYING DRAWINGS
[0020] The novel features and characteristics of the disclosure are set forth in the appended 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 detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

[0021] Figure 1 illustrates a schematic view of a test apparatus, according to an embodiment of the present disclosure.
[0022] Figure 2 illustrates a flow chart of measuring acoustics of an exhaust system, according to an embodiment of the present disclosure.
[0023] Figure 3 illustrates a bar graph of contribution of a pre-silencer in an insertion loss, according to an embodiment of the present disclosure.
[0024] Figure 4 illustrates a bar graph of contribution of a muffler in the insertion loss, according to an embodiment of the present disclosure.
[0025] Figure 5 illustrates a bar graph of contribution of the pre-silencer and the muffler in the insertion loss, according to an embodiment of the present disclosure.
[0026] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the test apparatus illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0027] While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiments thereof have been shown by the way of example in the figures and will be described 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.
[0028] It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify various features of the test apparatus for measuring acoustics of an exhaust, without departing from the scope of the disclosure. Therefore, such modifications are considered to be part of the disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skilled in the art having benefit of the description herein.
[0029] The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover non-exclusive inclusions, such that a device, assembly, mechanism, system, and method that comprises a list of components does not include only

those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system/assembly proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the assembly or system.
[0030] 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.
[0031] Unless the context of the disclosure describes or indicates a different interpretation, any reference to an object in the specification that is preceded by a definite or indefinite article, such as 'the', 'a', or 'an', should be understood to encompass both the singular and the plural forms of the object. Accordingly, “a” means “at least one/one or more”. The phrase “a/an X” may be construed as “at least one/one or more X”.
[0032] Embodiments of the present disclosure discloses a test apparatus for measuring acoustics of an exhaust system. The apparatus comprises a first chamber removably connected to a blower. The blower is configured to draw air from the surroundings and blows the drawn air into the first chamber at a predetermined speed. The first chamber is configured to heat the air to a predetermined temperature. The apparatus further comprises a second chamber, fluidly connected to the first chamber. The second chamber comprises a rotor and a stator. A first end of the second chamber receives the heated air from the first chamber. Furthermore, the apparatus comprises an outlet coupled to a second end of the second chamber for passage of the exhaust air from the second chamber. Rotation of the rotor on the stator exhausts the air from the second chamber in a pulsating manner to the outlet, to measure acoustics of the exhaust at the outlet.
[0033] The following paragraphs describe the present disclosure with reference to Figures. 1 to 5. In the figures, the same element or elements which have similar functions are indicated by the same reference signs. With general reference to the drawings, the test apparatus for measuring acoustics of the exhaust system is illustrated and generally identified with reference numeral (100).
[0034] Figure 1 depicts the test apparatus (100) for measuring acoustics of the exhaust system. The apparatus (100) comprises a first chamber (3) removably connected to a blower (1). The blower (1) is configured to draw air from the surroundings and blow the drawn air into the first

chamber (3) at a predetermined speed. The first chamber (3) is configured to heat the air to a predetermined temperature. The apparatus (100) further comprises a second chamber (9). The second chamber (9) is fluidly connected to the first chamber (3). The first chamber (3) comprises a heating coil (4) adapted to heat the air to the predetermined temperature to mimic the temperature of the exhaust system in real time. In an embodiment, the heating coil (4) may be a filament. The second chamber (9) comprises a rotor (10) and a stator (11). A first end (18) of the second chamber (9) receives the heated air from the first chamber (3). The first end (18) of the second chamber (9) receives the heated air from the first chamber (3) through a conduit (6). Furthermore, the apparatus (100) comprises an outlet (17) coupled to a second end (19) of the second chamber (9) for passage of the exhaust air from the second chamber (9). Rotation of the rotor (10) on the stator (11) exhausts the air from the second chamber (9) in a pulsating manner to the outlet (17), to measure acoustics of the exhaust at the outlet (17). The apparatus (100) further comprises a motor (12) coupled to the rotor (10) and is configured to rotate the rotor (10).
[0035] The pulsating exhaust of the air is achieved by passage of the air through the rotor (10) which is defines with a 25% opening and then through the stator (11) which is defined with a 50% opening to generate exhaust pulses. The stator (11) includes two 25% opening opposite to each other. Upon rotation of the rotor (10), the opening of the rotor (10) coincides with openings of the stator (11) twice in one complete rotation. That is, the rotor (10) and stator (11) arrangement cause the air to drain from the second chamber (9) twice to the outlet. Such air draining twice per rotation of the rotor (10) is termed as exhaust pulse of a second order.
[0036] Further, the apparatus (100) comprises a first valve (2) coupled to the blower (1). The first valve (2) is configured to drain the excess air from the blower (1), for instance, when the blower (1) draws excess air than required for supplying to the first chamber (3). Also, the apparatus (100) comprises a second valve (5) coupled to the first chamber (3). The second valve (5) is configured to drain the excess heated air from the first chamber (3), for instance, when excess air has been heated in the first chamber (3). Moreover, the apparatus (100) comprises a third valve (8) coupled to the conduit (6). The third valve (8) is configured to drain the excess heated air accumulated in the second chamber (9). Such accumulation of the heated air in the second chamber (9) may be due to partial or complete blockage of the rotor (10) and stator (11) arrangement. Further, when the speed of the heated air is higher than the

predetermined speed, then at least one of the second valve (5) and the third valve (8) is operated to an open condition to drain the excess air from the apparatus (100).
[0037] The apparatus (100) also comprises a sensor (7) coupled to the conduit (6). The sensor (7) is configured to measure the temperature of the heated air in the conduit (6). The electric input to the heating coil (4) may be varied based on the temperature measured by the sensor (7). Further, the apparatus (100) comprises a pulley arrangement (13) to transfer the rotational movement of the motor (12) to the rotor (10). The pulley arrangement (13) comprises a driver pulley (14), a driven pulley (15), and a driving component (16). The driving component (16) is one of a belt and a chain. Further, the ratio between the driver pulley and driven pulley may be different. In an exemplary embodiment, the ratio between the driver pulley and driven pulley is 1:2. Such motor (12) and pulley arrangement (13) provide necessary rotation per minute (rpm) of the rotor (10), required for measuring acoustics of the exhaust at the outlet (17).
[0038] In an embodiment, a method (200) for measuring acoustics of an exhaust is disclosed. As illustrated in Figure 2, the method (200) comprises drawing air (201) from the surrounding by a blower (1). Further, the method (200) comprises supplying the air (202) from the blower (1) to a first chamber (3). Furthermore, the method (200) comprises heating the air (203) in the first chamber (3) to a predetermined temperature. In addition, the method (200) comprises supplying the heated air (204) from the first chamber (3) to a second chamber (9). Also, the method (200) comprises rotating (205) a rotor (10) on a stator (11) to exhaust the air from the second chamber (9) in a pulsating manner to an outlet (17). Moreover, the method (200) comprises measuring (206) acoustics of the exhaust at the outlet (17).
[0039] In an embodiment, insertion losses are measured in the test apparatus (100) and in the vehicle, and both are compared for the purpose of validation. The insertion loss generally refers to the reduction in noise level attained by adding a barrier to a system. Figure 3 compares insertion losses due to the presence of a pre-silencer (barrier) at rpm 1000, 1500, and 2000. The insertion loss at 1000 rpm measured in the vehicle is approximately 5.5 dB, whereas the insertion loss at 1000 rpm measured in the test apparatus (100) (also referred as “rig level” interchangeably) is approximately 5.25 dB. Moreover, at 1500 rpm and 2000 rpm, the insertion loss in the vehicle is approximately 4.75 dB and in the test apparatus (100) the insertion loss is approximately 4.9 dB.

[0040] Figure 4 compares the insertion losses due to the presence of a muffler at rpm 1000, 1500, and 2000. The insertion loss at 1000 rpm measured in the vehicle is approximately 13 dB, whereas the insertion loss at 1000 rpm measured in the test apparatus (100) is also approximately 13 dB. Moreover, at 1500 rpm, the insertion loss in the vehicle is approximately 12.5 dB and in the test apparatus (100) the insertion loss is approximately 13 dB. Further, at 2000 rpm, the insertion loss in the vehicle is approximately 15 dB and in the test apparatus (100) the insertion loss is approximately 14.25 dB. Referring to Figure 5 which compares the insertion loss due to the presence of the muffler as well as the pre-silencer at rpm 1000, 1500, and 2000. The insertion loss at all the three rpm measured in the vehicle is approximately 18.75 dB, whereas the insertion loss at all the three rpm measured in the test apparatus (100) is approximately 18 dB.
[0041] The test apparatus (100) of the present disclosure is capable of measuring the acoustics of the exhaust system reliably before fitting into the vehicle. Therefore, the test apparatus (100) of the present disclosure mitigates the process of manufacturing the vehicle and re-developing repeatedly until the required standards are met. Consequently, the test apparatus (100) of the present disclosure decreases development time of the vehicle. Also, the test apparatus (100) of the present disclosure reduces requirement of enormous cost and efforts to meet the standard. In other words, the test apparatus (100) is cost-effective and requires minimum efforts to measure acoustics of the exhaust system.
[0042] It is to be understood that a person of ordinary skill in the art may develop a test apparatus (100) for measuring acoustics of an exhaust of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.
EQUIVALENTS
[0043] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[0044] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.
[0045] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
[0046] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a test apparatus (100)) having at least one of A, B, and C” would include but not be limited to the system that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in

the art would understand the convention (e.g., “a test apparatus (100) having at least one of A, B, or C” would include but not be limited to system that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
REFERRAL NUMERICALS

Numerical Particulars
1 Blower
2 First valve
3 First chamber
4 Heating coil
5 Second valve
6 Conduit
7 Sensor
8 Third valve
9 Second chamber
10 Rotor
11 Stator
12 Motor
13 Pulley arrangement

14
Driver pulley
15 Driven pulley
16 Driving component
17 Outlet
18 First end of the second chamber
19 Second end of the second chamber
100 Test apparatus
200 A method for measuring acoustics of an exhaust
201 Drawing air from the surrounding by a blower
202 Supplying the air from the blower to a first chamber
203 Heating the air in the first chamber to a predetermined temperature
204 Supplying the heated air from the first chamber to a second chamber
205 Rotating a rotor on a stator by a motor to exhaust air from the second chamber in pulsating manner to an outlet
206 Measuring acoustics of the exhaust at the outlet

We claim:
1. A test apparatus (100) for measuring acoustics of an exhaust system, the apparatus (100)
comprising:
a first chamber (3) removably connected to a blower (1), wherein the blower (1) is configured to draw air from the surroundings and blow the drawn air into the first chamber (3) at a predetermined speed, and the first chamber (3) is configured to heat the air to a predetermined temperature;
a second chamber (9), fluidly connected to the first chamber (3), comprises a rotor (10) and a stator (11), and a first end (18) of the second chamber (9) receives the heated air from the first chamber (3); and
an outlet (17) coupled to a second end (19) of the second chamber (9) for passage of the exhaust air from the second chamber (9); and
wherein rotation of the rotor (10) on the stator (11) exhausts the air from the second chamber (9) in a pulsating manner to the outlet (17), to measure acoustics of the exhaust at the outlet (17).
2. The apparatus (100) as claimed in claim 1, comprises a motor (12) coupled to the rotor (10) and is configured to rotate the rotor (10).
3. The apparatus (100) as claimed in claim 1, wherein the rotor (10) is defined with a 25% opening and the stator (11) is defined with a 50% opening to generate exhaust pulses of a second order.
4. The apparatus (100) as claimed in claim 1, comprises a conduit (6) disposed between the first chamber (3) and the first end (18) of the second chamber (9) for the passage of the heated air.
5. The apparatus (100) as claimed in claim 1, wherein the first chamber (3) comprises a heating coil (4) adapted to heat the air to the predetermined temperature to mimic the temperature of the exhaust system in real time.
6. The apparatus (100) as claimed in claim 1, comprises a first valve (2) coupled to the blower (1), the first valve (2) is configured to drain the excess air from the blower (1).

7. The apparatus (100) as claimed in claim 1, comprises a second valve (5) coupled to the first chamber (3), the second valve (5) is configured to drain the excess heated air from the first chamber (3).
8. The apparatus (100) as claimed in claim 1, comprises a third valve (8) coupled to the conduit (6), the third valve (8) is configured to drain the excess heated air accumulated in the second chamber (9).
9. The apparatus (100) as claimed in claim 1, comprises a sensor (7) coupled to the conduit (6), the sensor (7) is configured to measure the temperature of the heated air in the conduit (6).
10. The apparatus (100) as claimed in claim 1, comprises a pulley arrangement (13) to transfer the rotational movement of the motor (12) to the rotor (10).
11. The apparatus (100) as claimed in claim 9, wherein the pulley arrangement (13) comprises a driver pulley (14), a driven pulley (15), and a driving component (16).
12. The apparatus (100) as claimed in claim 10, wherein the driving component (16) is one of a belt and a chain.
13. A method (200) for measuring acoustics of an exhaust, the method (200) comprising:
drawing air (201) from the surrounding by a blower (1); supplying the air (202) from the blower (1) to a first chamber (3); heating the air (203) in the first chamber (3) to a predetermined temperature; supplying the heated air (204) from the first chamber (3) to a second chamber (9); rotating (205) a rotor (10) on a stator (11) to exhaust the air from the second chamber (9) in a pulsating manner to an outlet (17); and
measuring (206) acoustics of the exhaust at the outlet (17).