FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10 and Rule 13] TITLE: “A DEVICE FOR ATTENUATING ACOUSTIC ENERGY”
NAME AND ADDRESS OF THE APPLICANT:
TATA MOTORS PASSENGER VEHICLES LIMITED, an Indian company having its registered office at Floor 3, 4,, Plot-18, Nanavati Mahalaya, Mudhana Shetty Marg, BSE, Fort, Mumbai City, Maharashtra, 400 001.
NATIONALITY: Indian.
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
Present disclosure relates to a field of automobiles. Particularly, but not exclusively the present disclosure relates to devices for reduction/mitigation of noise emanating from mechanical parts of vehicles. Further, embodiments of the disclosure disclose a device for attenuating acoustic energy generated during operation of a radiator fan of the vehicle.
BACKGROUND OF THE DISCLOSURE
In general, there exists different types of vehicles such as hybrid, an electric or vehicles driven by internal combustion engine. Electric vehicles and hybrid electric vehicles (HEVs) include one or more traction motors which generate necessary power for driving the vehicle. While the electric vehicles include only traction motors, brushless motors, synchronous motors etc., the hybrid electric vehicles (HEVs) are powered by an internal combustion engine in combination with traction motors or electric motors. The traction motors or the electric motors use energy stored in power source such battery module and generate necessary power for driving the vehicle. Further, the traction motors present in any type of vehicle needs to be maintained at the optimal temperature level for better efficiency and long life which is achieved by using a cooling system. The cooling systems includes one or more cooling loops circulating coolants through the traction motors and batteries etc., using an electric pump. These cooling loops contained within a radiator having one or more blower fans to release heat from the coolant loops generated by forced induction. Typically, when the traction motor functions at full capacity, there is a rise in temperature within the traction motor. To control this rise in temperature of the traction motor, the blower fans of the cooling system must run at higher rpm and longer durations to cool the traction motor. Due to higher rpm of the fan and the longer durations, high acoustic noise is generated, causing inconvenience to the occupants within the vehicle and people around the vehicle.
The present disclosure is directed to overcome one or more above limitations stated above or any other limitation associated with the prior arts.
SUMMARY OF THE DISCLOSURE
The shortcomings of the prior art are overcome, and additional advantages are provided through the provision of system of 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.
In one non-limiting embodiment of the present disclosure discloses a device for attenuating acoustic energy. The device comprises a perforated panel and a ring coupled around a periphery of the perforated panel. Further, a plurality of apertures is defined around the ring and each aperture of the plurality of apertures are defined in a spaced apart configuration. At least one conduit is defined with a closed end and an open end. The at least one conduit with its open end is connected to each aperture of the plurality of apertures and the at least one conduit extends radially outward from the plurality of apertures configured to receive the acoustic energy for attenuating within the conduit.
In an embodiment, each conduit of the at least one conduit has a predefined diameter and length.
In an embodiment, the predefined diameter and length of the at least one conduit is tuned to attenuate a predetermined acoustic frequency range of the acoustic energy.
In an embodiment, the predetermined acoustic frequency ranges about 385-800 Hz.
In an embodiment, each conduit of the at least one conduit has varying diameter and length with respect to each other.
In an embodiment the ring is provided with a plurality of perforations.
In an embodiment, each aperture of the plurality of apertures are circumferentially spaced apart from each other.
The present disclosure further includes a vehicle comprising a traction motor mounted to a body frame of the vehicle. A radiator is mounted to the body frame of the vehicle for cooling the traction motor and wherein the radiator comprises at least one fan. A device is coupled to a shroud of the at least one fan to attenuate an airflow generated by the at least one fan. The device comprises a perforated panel and a ring coupled around the perforated panel. Further, a plurality of apertures is defined around the ring and each aperture of the plurality of apertures are defined in a spaced apart configuration. At least one conduit is defined with a closed end and an open end. The at least one conduit is provided around each aperture of the plurality of apertures and the at least one

conduit extends radially outward from the plurality of apertures configured to receive the acoustic energy for attenuating within the conduit.
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.
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
The novel features and characteristic of the disclosure are set forth in the appended claims. 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:
Figure 1a and 1b illustrates a sectional and a front view of a device for attenuating sound energy, in accordance with an embodiment of the present disclosure;
Figure 1c illustrates a perspective view of the device enclosing a fan, in accordance with an embodiment of the present disclosure;
Figure 2 illustrates a schematic view of an apparatus including the device of Figure 1 in assembled condition; and
Figures 3a- 3d illustrates graphs indicative of frequency Vs pressure of the sound at various blade frequency range, in accordance with an embodiment of the present disclosure.

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 structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which forms the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other mechanism for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
In the present disclosure, the word "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.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non¬exclusive inclusions, such that a setup, device, or process that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or process. 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.
Generally, electric vehicles include traction motors, synchronous motors, brushless motors etc, and the hybrid electric vehicles (HEVs) are powered by an internal combustion engine in combination with traction motors or electric motors. These traction motors employed in different type of vehicles need to be maintained at the optimal temperature level for better efficiency and performance which is accomplished by providing a cooling system as part of the vehicle. The cooling systems includes one or more cooling loops circulating coolants through the traction motors. The cooling loops are contained within a radiator having one or more blower fans to exchange heat from the coolant loops generated by a forced induction. Mostly, when the traction motor functions at full capacity, the traction motor tends to heat up. To control this heating of the traction motor, the blower fans of the cooling system must operate at higher rpm and for longer durations, thus generating high acoustic noise and vibration which in turn causes inconvenience to occupants within the vehicle. Accordingly, a device for attenuating acoustic energy of the present disclosure is configured to overcome the problems associated with the existing vehicles. The device of the present disclosure comprises a perforated panel and a ring coupled around a periphery of the perforated panel. A plurality of apertures is defined on the ring such that each aperture of the plurality of apertures are defined in a spaced apart configuration. Further, at least one conduit is defined with a closed end and an open end that are provided around each aperture of the plurality of apertures. The at least one conduit extends radially outward from the plurality of apertures and receives the acoustic energy for attenuating within the conduit. Therefore, the device of the present disclosure is suitable to attenuate the acoustic energy at a required frequency range.
Referring to Figures 1a to 2 which are exemplary embodiments of the present disclosure illustrating a device for attenuating acoustic energy [interchangeably referred as “device (100)”].

The device (100) comprises a perforated panel (10) designed to allow passage of air. Further, a ring (12) is defined around a periphery of the perforated panel (10). The perforations on the perforated panel (10) may be formed in an array of specified design with a plurality of perforations in a spaced apart configuration. However, such configuration of the formation of the plurality of perforation of the perforated panel (10) may not be limited to a formation depicted in figure 1a- 1c ,but can be change based on requirement. In an embodiment, the perforated panel (10) may be circular, rectangular or any other polygonal shape panel.
Further, the ring (12) is coupled along a periphery of the perforated panel (10) such that one edge of the ring (12) is connected to the perforated panel (10). The ring (12) may be a hollow structure, defined with a predetermined thickness and diameter. The ring (12) along with the perforated panel (10) forms an enclosure and accommodates a component for attenuating an acoustic energy. In an embodiment, the ring (12) can be coupled to the perforated panel (10) by any mechanical, thermal and adhesive means. The ring (12) comprises a plurality of apertures (20) defined around a surface of the ring (12). Each aperture of the plurality of apertures (20) are defined in a spaced apart configuration along the surface of the ring (12). In an embodiment, each aperture of the plurality of apertures (20) are spaced apart circumferentially from each other. The ring (12) is provided with a plurality of perforations (16). In an embodiment, a size of each aperture (20) defined on the ring (12) is larger than a size of the plurality of perforations (16) provided on the ring (12). The shape of the plurality of apertures (20) and the perforations (16) may be at least one of circular, rectangular, triangular or any polygonal shape, as per the requirement.
The device (100) further includes at least one conduit (30) which is defined with a closed end (CE) and an open end (OE). The at least one conduit (30) is provided around each aperture of the plurality of apertures (20) such that the at least one conduit (30) extends radially outward from the plurality of apertures (20). Further, the open end (OE) of each conduit (30) connected to the plurality of apertures (20) and the closed end (CE) is extended away based on a length of each conduit (30). in an embodiment, the at least one conduit (30) may have a predefined diameter and length based on requirement of attenuation of the acoustic energy. The predefined diameter and the length of the at least one conduit (30) is tuned to attenuate a predetermined acoustic frequency range of the acoustic energy of the air flow, which is generated by the component. Additionally, a number of conduits (30) and apertures (20) may be modified along the ring (12) based on the

frequency range of the acoustic energy to be muffled. In an embodiment, the device (100) is configured to attenuate the predetermined acoustic frequency ranging about 385-800 Hz,. In order to efficiently attenuate the acoustic energy, the diameter and length of each conduit (30) of the at least one conduit (30) may be varied with respect to each other. The at least one conduit (30) is configured to receive the acoustic energy with an airflow and muffle the acoustic energy without modifying the air flow as the open end (OE) of the conduit (30) is provided over the each of the aperture (20) and other end of the conduit (30) is sealed or defined as closed end (CE).
Further, the present disclosure discloses a vehicle comprising a traction motor [not shown in figures] mounted to a body frame [not shown in figures] of the vehicle. In order to cool the traction motor, a radiator (200) is provided within the vehicle. The radiator comprises one or more loops in fluid communication with traction motor. The one or more loops are configured to carry coolant to dissipate a heat generated by the traction motor by a forced convection. The force convention is achieved by the radiator having at least one fan (200). The at least one fan (200) is provided at an outlet side of the radiator to discharge the heat from the coolant by blowing air of required velocity over the one or more loops carrying the coolant. The at least one fan (200) is defined with an inlet side and an outlet side, such that the inlet side faces towards the one or more loop of the radiator.
The vehicle further includes the device (100) for attenuating the acoustic energy generated by the air flow generated by the at least one fan (200). The device (100) is coupled to a shroud of the at least one fan (200) such that, one or more blades (202) of the fan (200) are enclosed by the ring (12) and the perforated panel (10) as shown in Figure 2. Further, the device (100) is configured to absorb and attenuate the acoustic energy generated by the at least one fan (200) disposed within perforated panel (10) and the ring (12). The air flow generated by the fan (200) is partially restricted, as the air with acoustic energy is directed along the ring (12) and subsequently into the conduits (30) to muffle the acoustic energy. Additionally, the acoustic energy is further attenuated when the is air passed from the perforated panel (10). The perforated panel (10) enveloping the fan (200) allows air flow to expand and then enter into the at least conduit (30) for attenuating. The predefined diameter and length of the at least one conduit (30) can be tuned to attenuate a predetermined acoustic frequency range of the acoustic energy. Further, the acoustic frequency range is determined based on number of blades (202), speed of rotation and predetermined dimension of the at least one fan (200). In an embodiment, the acoustic frequency range is

determined by a blade pass frequency, thus reducing the blade pass frequency aids in reducing overall acoustic energy.
Experimental Examples
Various embodiments of determining acoustic frequency and attenuating acoustic energy by the device (100) shall now be explained. It will be appreciated by a person skilled in the art that the embodiments described below are non-limiting. Various modifications, additions, alterations, and improvements may be made by a person skilled in the art and are to be construed as being within the scope of this disclosure.
In an experiment set up, a microphone is placed at a distance of 1meter and in-line to a fan centre. The acoustic energy values at various blade pass frequencies are recorded by the microphone with and without mounting the device (100). Based on the recorded values, as mentioned below in the table 1.1. to 1. 4 are indicative of the plotted graphs of frequency Vs pressure of the sound as shown in Figures 3a-3b, it is observed that application of the device (100) with the radiator of the vehicle effectively reduces a noise generated by the fan (200). Approximately 3.6 dB(A) improvement is observed in the blade pass frequency. The below tables indicate values for attenuating 385-800Hz frequency range.
A plurality of parameters is considered for determining a blade pass frequency range.
For case 1: the below parameters are as follows
a) Fan Dimension: 310 mm; b) No of Fan Blades: 7 Blades; c) Max Fan Rpm: 4700 rpm
Thus, Blade pass frequncy, Fn = [(Max Fan rpm)/60] x No.of blades
Fn=4700/60 x 7 =548 Hz
Based on the input frequency, the sound attenuator with the number of conduits, height of the conduits and diameter of the conduits, the spaced apart configuration of the conduit is determined.

Table 1.1 (Figure 3a) Table 1.2 (Figure 3b)

In an embodiment, the perforated panel (10) the ring (12) and the conduits (30) may be manufactured by at least one of a metal, composite material, and any other suitable material.
In an embodiment, the device (100) according to present disclosure provides a cost-effective solution for controlling and attenuating acoustic frequency of the air flow.
In an embodiment, the size, configuration of the components of device (100) may be varied according to the application requirement.
In an embodiment, the present disclosure provides the device (100) that is simple, robust, and compact.
In an embodiment, the device (100) of the present disclosure enhances Noise, vibration, and harshness parameter of the vehicle, thereby keeps occupants within the vehicle from the intense noise of the components, such as traction motor or at least one fan (200).
Equivalents:
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.
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 system having at least one of A, B, and C” would include but not be limited to systems 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 system having at least one of A, B, or C” would include but not be limited to systems 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 NUMERALS

Reference Number Description
100 Device
10 Perforated panel
12 Ring
16 Plurality of perforations
20 Plurality of apertures
30 Conduit
200 Fan
202 blades

We claim:
1. A device (100) for attenuating acoustic energy, the device (100) comprising:
a perforated panel (10);
a ring (12) coupled around a periphery of the perforated panel (10);
a plurality of apertures (20) defined on the ring (12), wherein each aperture of the plurality of apertures (20) are defined in a spaced apart configuration;
at least one conduit (30) defined with a closed end (CE) and an open end (OE), the at least one conduit (30) with its open end (OE) is connected to each aperture of the plurality of apertures (20), wherein the at least one conduit (30) extends radially outward from the plurality of apertures (20), and
wherein the at least one conduit (30) is configured to receive the acoustic energy for attenuating within the conduit (30).
2. The device (100) as claimed in claim 1, wherein each conduit (30) of the at least one conduit (30) has a predefined diameter and length.
3. The device (100) as claimed in claim 2, wherein the predefined diameter and length of the at least one conduit (30) is tuned to attenuate a predetermined acoustic frequency range of the acoustic energy.
4. The device (100) as claimed in claim 3, wherein the predetermined acoustic frequency ranges about 385-800 Hz.
5. The device (100) as claimed in claim 1, wherein each conduit (30) of the at least one conduit (30) has varying diameter and length with respect to each other.

6. The device (100) as claimed in claim 1, wherein the ring (12) is provided with a plurality
of perforations (16).
7. The device (100) as claimed in claim 1, wherein each aperture of the plurality of apertures
(20) are circumferentially spaced apart from each other.
8. A vehicle comprising
a traction motor mounted to a body frame of the vehicle;
a radiator mounted to the body frame of the vehicle for cooling the traction motor, wherein the radiator comprises at least one fan (200);
a device (100) coupled to a shroud of the at least one fan (200) to attenuate an airflow generated by the at least one fan (200), wherein the device (100) comprises;
a perforated panel (10);
a ring (12) coupled around a periphery of the perforated panel (10) and encircling a plurality of blades (202) of the least one fan (200);
a plurality of apertures (20) defined around the ring (12), wherein each aperture of the plurality of apertures (20) are defined in a spaced apart configuration;
at least one conduit (30) defined with a closed end (CE) and an open end (OE), the at least one conduit (30) with its open end (OE) is connected to each aperture of the plurality of apertures (20), wherein the at least one conduit (30) extends radially outward from the plurality of apertures (20), and
wherein the at least one conduit (30) is configured to receive and attenuate the acoustic energy of the airflow generated by the at least one fan (200), within the conduit (30).

9. The vehicle as claimed in claim 8, wherein each conduit (30) of the at least one conduit (30) has a predefined diameter and length.
10. The vehicle as claimed in claim 8, wherein the predefined diameter and length of the at least one conduit (30) is tuned to attenuate a predetermined acoustic frequency range of the acoustic energy.
11. The vehicle as claimed in claim10, wherein the predetermined acoustic frequency range is 385-800 Hz
12. The vehicle as claimed in claim 10, the acoustic frequency range is determined based on number of blades (202), speed of rotation and predetermined dimension of the at least one fan (200).
13. The vehicle as claimed in claim 8, wherein the at least one fan (200) is defined with an inlet side and an outlet side, and the device (100) is mounted on the outlet side of the at least one fan (200).