Vehicle Interior Noise Prediction by Using Experimental Methods and Analysis - Report Example

Vehicle Interior Noise Prediction by Using Experimental Methods and Analysis Name Institution Name Date 1.0 Introduction Vehicles continue been an integral component in the society and efficiency of the vehicles is crucial. Thousands of people spend most of their time in vehicles: therefore, sound quality and comfort continue to become important (Braun et al. 2013). Numerous studies have been done around sound quality prediction and interior sound quality evaluation and these variables have improved the vehicle design. Huang et al. (2016) state that interior sound does not cause hearing damage but negatively affect passenger physiology and psychology. In addition, the consumer's purchase behavior is influenced by many factors including sound quality prediction (Seddeq et al. 2013). In the design of vehicles and demands from consumers, the design has shifted to environmental concerns because of pollutions and negative consequences of the use of certain types of absorption materials. Background 1..1 Sources of Vehicle Noise Liu, Fard, and Davy (2016) references Biot theory saying that three basic sound waves propagate in a porous material. These three sound waves are one shear wave and two compression waves. The question to be answered is what the sources of vehicle noise are. Liu, Fard, and Davy (2015) states that one of the sources of noise in the vehicle is structure borne noise excitation. Chen, Wang, and Zan (2011) states that different forms of excitations exist, which includes road excitations, engine mount excitations, sound excitations of the engine, wind excitations, and interior noise excitations. All these noises are associated with vibration of different body parts including the panel system and design systems. The focus is on new cars but it is also imperative to note more noises are produced by old cars (Engels et al. 2013; Rus, Normunira and Rahim, 2014). Car designers have implemented different measures in absorbing sounds on the engine and other casing parts such as placing rubber between the metallic parts, and also frequent greasing to reduce the noise (Chen, Wang, and Ma, 2012; Küçük and Korkmaz, 2012). However, the focus is the interior noise, and the solution is the inclusion of sound absorption materials in strategic areas in the interior of the car. 1..2 Sound Absorption and Control Ersoy and Küçük (2009) states that sound absorption materials are important and the sound insulation method utilizes materials such as mineral fibers, foam, wool and their composites. In the utilization of these different materials, placing of the absorptive materials under the carpet, behind the pillar and door panel, and above the headliner. Liu, Fard, and Davy (2016) presents that porous materials are used in the interior of vehicles such as door panels, seats, roof lining, floor carpet and dashboard to reduce the amount of noise while also enhancing the cabin acoustic quality. These different designs and absorption strategies focus on the passenger’s cabin area (Huang et al. 2016). Designers and automobile manufacturers want to provide the highest quality noise absorption strategy, which Küçük and Korkmaz (2012) states that it is possible through the continuous development of databases of measurements and tests. The developed database is used to improve the knowledge of different materials and applicability of the materials in specific body design objectives. For example, a given material is appropriate for roof lining while another is appropriate for the dashboard. Hence, determining the appropriate noise absorption material is paramount. Zent and Long (2007) enumerates three methods of noise control to reduce vehicle interior noise. These three methods are the use of sound absorbers in both the interior and exterior, use of barriers and other strategies to prevent sound from entering the passenger compartment and the third approach is the reduction of vibration and noise sources. Liu, Fard, and Davy (2015) states that metal panels in the automobile create several noise vibration and harshness, which are sometimes difficult to understand. However, the authors’ state the problem can be solved through the use of sound absorbing materials and the continuous studies on materials is integral (Mohanty and Fatima, 2013; Rus, Normunira and Rahim, 2014). The entire premise of studies and research is to increase the amount of knowledge and guide in the design and construction of automobiles. Knowledge Gap Liu, Fard, and Davy (2015) presents the example of structure-borne noise excitation in indicating studies on sound insulation and absorption should incorporate numerous designs and fundamentals of the cars. Liu, Fard, and Davy (2015) and Mohanty and Fatima (2013) analysis indicates there are areas where studies have not be done and research should be done to improve the sound absorption. Liu et al. (2016) did a study focusing on 3D technology through the additive process. Liu et al. (2016) state that it is an emerging technology that has not been studied in relevance to vehicle noise absorption. These are an example of studies that indicates limited knowledge on sound absorption and the requirement of doing more studies and experiments to understand the effectiveness of different materials in noise absorption (Forssén et al. 2012; Rus, Normunira and Rahim, 2014). Hence, it is the purpose of this to increase the knowledge and contribute to literature vehicle noise absorption strategies and methods. Aim The aim of this project is to optimize performance of the vehicle cavity and reduce the noise occurring inside the vehicle by practical experiment passengers’ cabin Objectives The following are the research objectives: To predict impact of interior on the acoustic fast response of the cavity system To measure an acoustic model and select multilayer of an acoustic material in the interior noise To improve the sound insulation performance by using experimental methods Research Questions The following are the research questions: i. What are some of the materials to reduce noise ii. Does increasing the density or thickness of acoustic absorption materials reduce noise iii. What are the effectiveness of different materials in noise absorption ability Significance and Innovation It is imperative to note that characteristic and doing tests on sound absorbing materials is time-consuming and cost. Databases and different systems are developed to reduce these costs since designers can refer. Liu, Fard, and Jazar (2015) states that the normal processes are measuring the normal sound absorption coefficient and some of the parameters studied include thermal characteristics length, viscosity, tortuosity, porosity, airflow resistivity and thickness. Pursuing the current study and research is crucial in increasing the amount of data and information relative to sound absorption (Küçük and Korkmaz, 2012). The changing technological environment including the technological advancement means that continues studies have to be done to determine the appropriate sound absorption materials relative to changing working conditions. For example, the 3D technology is a new format that utilizes additive manufacturing, meaning consideration of such technologies can widen the scope of database content. Hence, the current study and experimental study expands on the idea of creating a database through understanding different materials. Expected Outcome The purpose and aims of are to reduce noises from passenger’s cabin. In accomplishing the study, some of the information the researcher aims to find include strategies and methods that can be used to improve vehicle interior noise absorption. The entire process depends on understanding the source of the noise, which can be achieved through noise prediction. Understanding the sources of noise from a vehicle enables determination of the right absorption material, and the overall design of the cabin. Hence, knowing the sources of the noise and understanding the strategies to eliminate or minimize the noise are crucial, and it is the basis of the current study. 2.0 Literature Review Acoustic Material and Absorption Ersoy and Küçük (2009) presents molding of premix, preheating and lamination resulting in a porous laminated composite material that is able to absorb sound in the frequency range of between 500 and 2000 Hz. Other material combination such as metal foam has a higher absorption coefficient estimated at between 2000 and 4000 Hz. Sometimes, wasted rubber particles are used for insulation and sound absorption purposes but the problem is that it is not effective and requires matching with polystyrene particles and polypropylene particles, resulting in a product with better absorption capacity. Ersoy and Küçük (2009) indicates continuous research and studies are important because new materials and the combination of different materials ensures a better absorption material. Huang et al. (2016) advice that it is important to analyze different materials relative to the design objectives. Therefore, in determining the appropriate acoustic material and absorption capacity, the design should factor noises from different sources. Liu et al. (2016) state that numerous studies have been done to understand porous fibrous materials and acoustic performance. The authors take a completely different approach in appreciating acoustic porous materials and employed additive manufacturing processes. Liu et al. (2016) the results of the study indicated that 3D printed PPM had better sound absorption at low to medium frequencies. The study indicates alternative approaches of creating insulation and fabrication of porous materials. For example, combining the new technologies with the traditional absorption coefficient enables creating new formulations that reflect the changing noise and sound effects. Prediction of Vehicle Interior Sound Quality Studies on the prediction of vehicle interior sound quality have been done for a long time and the outcomes of these studies can be categorized into machine learning based and psychoacoustics based methods. According to Huang et al. (2016), two psychoacoustics based method exist, which are octave band based analysis and the critical band based method. The benefit of the octave band based analysis is the simple and fast approach in completing calculations. The critical band based method targets human sensation of loudness, and it is preferred to the octave band based analysis since it is accurate and more effective (Hao, Zhao, and Chen, 2013; Küçük and Korkmaz, 2012). Other variables associated with the critical based method include tonality, articulation index, fluctuation strength, roughness, and sharpness. The machine learning based method addresses the complexity between the acoustic performance and human hearing (Yilmaz et al. 2013). The machine technique is used to study characteristics of sound, which individual psychoacoustics approach cannot fulfill. Numerous techniques are associated with the machine learning method including different regression based techniques integrating numerous variables and design objectives. 3.0 Research Method Approach and Methodology The collection of the data and the design of the processes that includes two microphone transfer function method according to ASTM E1050-98 and ISO 10534-2, which are the international standards specifications. The general design of the arrangement of numerous components used in testing the materials is Source (Ersoy and Küçük, 2009, p. 216) In extension, the methodological approach borrows heavily from Liu, Fard, and Jazar (2015): The sound absorption coefficients are measured through the help of two microphone impedance tube test The obtained sound absorption coefficients are then analyzed through the use of theoretical models such as the Komatsu model Other data are then measured from the laboratory such as the density and thickness Correlation and simulation processes are incorporate in the entire study to validate and improve the quality of the entire measurement and experiment Project Plan The project will take one semester. The image indicated shows the numerous activities that will be done within a period of twelve weeks. An extensive literature review is crucial because it guides the researcher and provides opportunity in understanding the circumstances surrounding the study, and the influences of numerous processes. The following chart summarizes the numerous activities to be done at different periods of the study: Budget The researcher aims to utilize personal and institutional resources in completing the study. Most of the testing and records will employ the institution resources while the researcher will use personal resources in writing the report and other objectives of analyzing the data: Required Item Estimated Cost and Source/Support Vehicle trim materials These materials are available at RMIT workshop. In addition, arrangements can be made with the laboratory management to avail some of these materials Test tube Different variety of equipment and tools are available in the laboratory. The study will focus on the available tools and equipment Monitors and computer system Available in the laboratory Audio and sound system (microphone and speakers) AU$ 240 Software and support system Available in the laboratory and further assistance in the use of the software and other systems can be arranged with the management or laboratory/workshop technicians Laptop and CAD technology The researcher will utilize his own laptop and resources to analyze the data and write the report. The researcher already has additional resources that can be utilized in completing the study/research 4.0 Possible Obstacles Acquiring the necessary technique and skill in the manipulation of apparatus and appreciating the use of different instruments apparatus (Holguín-Veras et al. 2013) Ineffective in making observations Poor laboratory condition and unavailability of important resources (Asdrubali, Schiavoni, and Horoshenkov, 2012; Küçük and Korkmaz, 2012) Ineffective recording of experiment readings Doing the wrong calculations and competency to create and understand graphical representation References Asdrubali, F., Schiavoni, S. and Horoshenkov, K.V., 2012. A review of sustainable materials for acoustic applications. Building Acoustics, vol. 19, no. 4, pp. 283-311. Braun, M.E., Walsh, S.J., Horner, J.L., and Chuter, R., 2013. Noise source characteristics in the ISO 362 vehicle pass-by noise test: Literature review. Applied Acoustics, vol. 74, no. 11, pp. 1241-1265. Chen, S.M., Wang, D.F. and Zan, J.M., 2011. Interior noise prediction of the automobile based on hybrid FE-SEA method. Mathematical Problems in Engineering, pp. 1-20. Chen, X., Wang, D. and Ma, Z., 2012. Simulation on a car interior aerodynamic noise control based on statistical energy analysis. Chinese Journal of Mechanical Engineering, vol. 25, no. 5, pp. 1016-1021. Engels, H.W., Pirkl, H.G., Albers, R., Albach, R.W., Krause, J., Hoffmann, A., Casselmann, H. and Dormish, J., 2013. Polyurethanes: versatile materials and sustainable problem solvers for today’s challenges. Angewandte Chemie International Edition, vol. 52, no. 36, pp. 9422-9441. Ersoy, S. and Küçük, H., 2009. Investigation of industrial tea-leaf-fibre waste material for its sound absorption properties. Applied Acoustics, 70(1), pp.215-220. Forssén, J., Tober, S., Corakci, A.C., Frid, A. and Kropp, W., 2012. Modelling the interior sound field of a railway vehicle using statistical energy analysis. Applied Acoustics, vol. 73, no. 4, pp. 307-311. Hao, A., Zhao, H. and Chen, J.Y., 2013. Kenaf/polypropylene nonwoven composites: the influence of manufacturing conditions on mechanical, thermal, and acoustical performance. Composites Part B: Engineering, vol. 54, pp. 44-51. Holguín-Veras, J., Marquis, R., Campbell, S., Wojtowicz, J., Wang, C., Jaller, M., Hodge, S., Rothbard, S. and Goevaers, R., 2013. Fostering the use of unassisted off-hour deliveries: operational and low-noise truck technologies. Transportation Research Record: Journal of the Transportation Research Board, (2379), pp.57-63. Huang, H.B., Huang, X.R., Li, R.X., Lim, T.C. and Ding, W.P., 2016. Sound quality prediction of vehicle interior noise using deep belief networks. Applied Acoustics, vol. 113, pp. 149-161. Küçük, M. and Korkmaz, Y., 2012. The effect of physical parameters on sound absorption properties of natural fiber mixed nonwoven composites. Textile Research Journal, vol. 82, no. 20, pp. 2043-2053. Liu, Z., Fard, M. and Davy, J., 2016. Acoustic properties of the porous material in a car cabin model. In Twenty-Third International Congress on Sound and Vibration (pp. 1-8). International Institute of Acoustics and Vibration. Liu, Z., Fard, M. and Davy, J.L., 2015. The effects of porous materials on the noise inside a box cavity. In Proceedings of the 22nd International Congress on Sound and Vibration. Liu, Z., Fard, M. and Jazar, R., 2015. Development of an acoustic material database for vehicle interior trims (No. 2015-01-0046). SAE Technical Paper. Liu, Z., Zhan, J., Fard, M. and Davy, J.L., 2016. Acoustic properties of a porous polycarbonate material produced by additive manufacturing. Materials Letters, vol. 181, pp. 296-299. Mohanty, A.R. and Fatima, S., 2013. An overview of automobile noise and vibration control. Noise & Vibration Worldwide, vol. 44, no. 6, pp. 10-19. Rus, A.Z.M., Normunira, N.M. and Rahim, R.A., 2014. Influence of multilayer textile biopolymer foam doped with titanium dioxide for sound absorption materials. In Key Engineering Materials (Vol. 594, pp. 750-754). Trans Tech Publications. Seddeq, H.S., Aly, N.M., Marwa A, A. and Elshakankery, M.H., 2013. Investigation on sound absorption properties for recycled fibrous materials. Journal of Industrial Textiles, vol. 43, no. 1, pp. 56-73. Yilmaz, N.D., Powell, N.B., Banks-Lee, P. and Michielsen, S., 2013. Multi-fiber needle-punched nonwoven composites: effects of heat treatment on sound absorption performance. Journal of Industrial Textiles, vol. 43, no. 2, pp. 231-246. Zent, A. and Long, J.T., 2007. Automotive sound absorbing material survey results (No. 2007-01-2186). SAE Technical Paper. Read More