scholarly journals A comparison between hybrid method technique and transfer matrix method for design optimization of vehicle muffler

2021 ◽  
Vol 49 (2) ◽  
pp. 494-500
Author(s):  
Barhm Mohamad ◽  
Jalics Karoly ◽  
Andrei Zelentsov ◽  
Salah Amroune
Keyword(s):  
Transmission Loss ◽  
Complex Structure ◽  
Design Parameters ◽  
Element Analysis ◽  
Vehicle Noise ◽  
Race Car ◽  
Fea Model ◽  
Important Approach ◽  
Machine Analysis ◽  
Perforated Pipe

Hybrid mufflers are now commonly equipped to decrease vehicle noise and are a crucial tool for regulation of the acoustic system. In order to ensure optimum engine efficiency, the system is intended to dump the strength of the acoustic pulses generated from the engine, and the back pressure created by these systems must be held to a minimum. Typically, modern mufflers have a complex structure of chambers and flow paths. There are a number of mechanisms for sound dampening that operate to silence the sound flowing through a muffler and piping device. This research introduces an important approach to optimize the transmission loss of hybrid muffler Formula student race car (FS) by using both experimental and analytical methods. For this analysis, two methods of calculation were chosen. The muffler has a complex partition located within the muffler chamber, which is a perforated pipe. For the creation of the Finite Element Analysis (FEA) model in AVL BOOST solver and another commercial advanced design software, the muffler CAD file was developed. Experimental measurements using a two-load method validated the FEA model. Reliable tests were conducted to verify the design parameters and optimize the muffler's transmission loss (TL) after the model was checked. The findings of experimental and machine analysis are included in the paper. For different measurement methods, recommendations are made for achieving optimum transmission loss curves.

scholarly journals A hybrid method technique for design and optimization of Formula race car exhaust muffler

2020 ◽  
Vol 11 (2) ◽  
pp. 174-180
Author(s):  
Barhm Mohamad ◽  
Jalics Karoly ◽  
Andrei Zelentsov ◽  
Salah Amroune
Keyword(s):  
Computer Aided Design ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Design Parameters ◽  
Piping System ◽  
Element Analysis ◽  
Software Analysis ◽  
Race Car ◽  
Fea Model ◽  
Car Exhaust

AbstractIn this work a multilevel Computational Fluid Dynamics (CFD) analysis has been applied for the design of a Formula race car exhaust muffler with improved characteristics of sound pressure level (SPL) and fluid dynamic response. The approaches developed and applied for the optimization process range from the 1D to fully 3D CFD simulation, exploring hybrid approaches based on the integration of a 1D model with 3D tools. Modern mufflers typically have a complex system of chambers and flow paths. There are a variety of sound damping and absorbing mechanisms working to quiet the sound flowing through a muffler and piping system. Two calculation methods were selected for this study. The muffler has a complex inner structure containing perforated pipe and fiber material. Computer-aided design (CAD) file of the muffler was established for developing Finite Element Analysis (FEA) model in AVL BOOST v2017 and another commercial advanced design software (SolidWorks 2017). FEA model was made to monitor the flow properties, pressure and velocity. After the model was verified, sensitivity studies of design parameters were performed to optimize the SPL of the muffler. The software analysis results are included in the paper. Recommendations are made for obtaining smoother SPL curves for various measurement methods.

Electrothermal Characterization of Doped-Si Heated Microcantilevers Under Periodic Heating Operation

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Sina Hamian ◽  
Andrew M. Gauffreau ◽  
Timothy Walsh ◽  
Jungchul Lee ◽  
Keunhan Park
Keyword(s):  
Microelectromechanical Systems ◽  
Transfer Functions ◽  
Design Parameters ◽  
Periodic Heating ◽  
Element Analysis ◽  
Full Spectrum ◽  
Frequency Dependent ◽  
Thermal Transfer ◽  
Fea Model

This paper reports the frequency-dependent electrothermal behaviors of a freestanding doped-silicon heated microcantilever probe operating under periodic (ac) Joule heating. We conducted a frequency-domain finite-element analysis (FEA) and compared the steady periodic solution with 3ω experiment results. The computed thermal transfer function of the cantilever accurately predicts the ac electrothermal behaviors over a full spectrum of operational frequencies, which could not be accomplished with the 1D approximation. In addition, the thermal transfer functions of the cantilever in vacuum and in air were compared, through which the frequency-dependent heat transfer coefficient of the air was quantified. With the developed FEA model, design parameters of the cantilever (i.e., the size and the constriction width of the cantilever heater) and their effects on the ac electrothermal behaviors were carefully investigated. Although this work focused on doped-Si heated microcantilever probes, the developed FEA model can be applied for the ac electrothermal analysis of general microelectromechanical systems.

scholarly journals Effects of Different Interface Forms on Mechanical Properties of Steel Self-Compacting Concrete Composite Beams

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Chengzhi Wang ◽  
Xin Liu ◽  
Wei Liu ◽  
Zhiming Li
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Bearing Capacity ◽  
Composite Structure ◽  
Mechanical Performance ◽  
Complex Structure ◽  
Self Compacting Concrete ◽  
Element Analysis ◽  
Shear Connectors ◽  
Fea Model

In the water resources allocation project in Pearl River Delta, in order to optimize the structural design, the deep buried tunnel adopts the composite lining structure. However, the weakest link in a complex structure is the connection between two different interfaces. This paper reports the findings of an experimental study that was undertaken to investigate the interface mechanical performance of steel self-compacting concrete composite structure subjected to cyclic loads. In this study, different shear connectors are considered, and six different specimens were designed and tested, respectively. The test is used to research the effect of the different shear connectors on the bearing capacity and interface mechanical properties of composite structure in an experimental study. According to these test results, a detailed analysis was carried out on the relationships, such as the stress-strain and load-displacement relationships for the specimen. These tests show that the shear connectors will significantly enhance the bearing capacity and interface mechanical properties of the composite structure. Among them, the comprehensive performance of the specimens using the stud-longitudinal ribs shear connectors is the best. Additionally, a finite element analysis (FEA) model was developed. The comparison of the simulation results with the experimental results shows that this FEA is applicable for this type of experiment.

scholarly journals Vibroacoustic Modeling and Path Control of Air-Borne Axle Whine Noise

2014 ◽  
Vol 6 ◽  
pp. 248362
Author(s):  
Dong Guo ◽  
Guohua Sun
Keyword(s):  
Transmission Loss ◽  
Gear Tooth ◽  
Contact Process ◽  
Element Model ◽  
Housing System ◽  
Design Parameters ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Vehicle Noise ◽  
Gear Mesh

The axle whine noise will eventually affect the vehicle noise performance. In this study, a systematic modeling approach is developed to analyze the axle whine problem by considering the hypoid gear mesh from the tooth contact process as well as the system dynamics effect with gear design parameters and shaft-bearing-housing system taken into account. Moreover, the tuning of the dominant air-borne path is modeled analytically by using the sound transmission loss idea. First, gear tooth load distribution results are obtained in a 3-dimensional loaded tooth contact analysis program. Then mesh parameters are synthesized and applied to a linear multibody gear dynamic model to obtain dynamic mesh and bearing responses. The bearing responses are used as the excitation force to a housing finite element model. Finally, the vibroacoustic analysis of the axle is performed using the boundary element method; sound pressure responses in the axle surface are then simulated. Transmission losses of different panel partitions are included in the final stage to guide the tuning of air-borne paths to reduce the radiated axle whine noise. The proposed approach gives a more in-depth understanding of the axle whine generation and therefore can further facilitate the system design and trouble-shooting.

Mathematical Model and Finite Element Analysis of Acoustics Performance of Composite Exhaust Muffler

2014 ◽  
Vol 651-653 ◽  
pp. 984-987
Author(s):  
Xiao Dong Li ◽  
Xin Tan Ma
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Transmission Loss ◽  
Complex Structure ◽  
Three Dimensional ◽  
Sound Field ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Vibration Simulation ◽  
Three Dimensional Finite Element

. Since the theory of one-dimensional plane wave is difficult to predict the internal sound field of the complex structure muffler accurately. Mathematical model of the composite muffler is analyzed, and the three-dimensional finite element method is adopted to establish the acoustic model in this paper. Transmission loss and characteristics of internal sound field of the composite muffler are calculated through sound and vibration simulation. Influential effect of the fluid on transmission loss is analyzed. The analysis method and conclusions provide a basis for the design of composite muffler.

Engineering Applications of Satellite Structural Optimization Utilizing ANSYS/CATIA

2011 ◽  
Vol 110-116 ◽  
pp. 1567-1575
Author(s):  
Jia Mao ◽  
Wei Hua Zhang
Keyword(s):  
Optimization Design ◽  
Parametric Design ◽  
Reference Value ◽  
Optimization Method ◽  
Design Parameters ◽  
Element Analysis ◽  
Fea Model ◽  
Satellite Platform ◽  
Weight Design ◽  
Work Done

A structured frame for the design optimization problem of satellite platform structure was established through the definition, flow and modification research of design parameters in the ANSYS/CATIA system. Problems with creating complex satellite structure FEA (Finite Element Analysis) models were discussed, including the idealization of real structure, as well as embedment of APDL (ANSYS Parametric Design Language) programme developed specially for the pre-processing and post-processing of FEA model. The optimization model was established under structural design requirements, and a graded optimization method was applied for calculation. Light-weight design schemes for two satellite platform structure were obtained through the subsequently optimization implemented using approaches put forward previously. The optimization design problems of two satellite platform structure were settled well, and work done in this paper provides certain reference value for optimization of other spacecraft structures.

Power Packaging Thermal and Stress Model for Quick Parametric Analyses

2017 ◽  
Author(s):  
L. M. Boteler ◽  
S. M. Miner
Keyword(s):  
Thermal Stresses ◽  
Thermal Analyses ◽  
Computational Time ◽  
Design Parameters ◽  
Power Module ◽  
Element Analysis ◽  
Resistor Network ◽  
Fea Model ◽  
Wide Range ◽  
Packaging Structure

This work presents an easy to use approach to quickly estimate the device temperatures and thermal stresses in a generic high power module. A low order model was developed in MATLAB using a combination of numerical-analytical approach and a 3D nodal resistor network to calculate device temperatures and thermal stresses. The model assumes a heat flux generated at the top of each device which is dissipated through the packaging structure and removed by convection. The temperature distribution is used to calculate thermal stresses throughout the package. This method eliminates computer aided drawings (CAD) in favor of numerical parameters that can be easily and quickly varied over a wide range. The resistor network solves quickly in MATLAB, enabling fast, iterative thermal analyses and design through parametric studies of the chip dimensions, number of chips, chip layout, material types, cooling solutions, etc. The model is adaptable to any number of devices and board layers. The MATLAB model reduced the computational time by 97% compared to an equivalent SOLIDWORKS finite element analysis (FEA) model and that does not include the time required to generate the CAD model and verify mesh convergence and mesh independence. Temperatures from the network model were within 5°C and stresses were within 30% of the values obtained from the FEA model. The ability to quickly assess the thermal and stress effects of a wide variety of power module design parameters during the initial design process, without the complexity of a full FEA analysis, with reasonable results can significantly improve the final module.

Tire Bead Overheating in Urban Buses and Trucks Using Drum Brake Systems

1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier
Keyword(s):  
Heat Transfer ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Energy ◽  
Structural Integrity ◽  
Experimental Temperature ◽  
Temperature Profiles ◽  
Element Analysis ◽  
Drum Brake ◽  
Fea Model

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.

A Simplified Design Model for Modular Steel Buildings Subject to Vapor Cloud Explosions (VCEs)

2020 ◽  
Vol 14 ◽  
Author(s):  
Osama Bedair
Keyword(s):  
Dynamic Response ◽  
Minimum Cost ◽  
Design Parameters ◽  
Front Wall ◽  
Steel Buildings ◽  
Element Analysis ◽  
Analysis And Design ◽  
Vapor Cloud ◽  
Building Components ◽  
Analytical Expressions

Background: Modular steel buildings (MSB) are extensively used in petrochemical plants and refineries. Limited guidelines are available in the industry for analysis and design of (MSB) subject to accidental vapor cloud explosions (VCEs). Objectives: The paper presents simplified engineering model for modular steel buildings (MSB) subject to accidental vapor cloud explosions (VCEs) that are extensively used in petrochemical plants and refineries. Method: A Single degree of freedom (SDOF) dynamic model is utilized to simulate the dynamic response of primary building components. Analytical expressions are then provided to compute the dynamic load factors (DLF) for critical building elements. Recommended foundation systems are also proposed to install the modular building with minimum cost. Results: Numerical results are presented to illustrate the dynamic response of (MSB) subject to blast loading. It is shown that (DLF)=1.6 is attained at (td/t)=0.4 for front wall (W1) with (td/T)=1.25. For side walls (DLF)=1.41 and is attained at (td/t)=0.6. Conclusions: The paper presented simplified tools for analysis and design of (MSB) subject accidental vapor cloud blast explosions (VCEs). The analytical expressions can be utilized by practitioners to compute the (MSB) response and identify the design parameters. They are simple to use compared to Finite Element Analysis.

Acoustic meta-silencer: Toward enabling ultrawide-band air-permeable noise barrier

2021 ◽  
pp. 107754632110011
Author(s):  
Mohammad Javad Khodaei ◽  
Amin Mehrvarz ◽  
Reza Ghaffarivardavagh ◽  
Nader Jalili
Keyword(s):  
Heat Transfer ◽  
Design Methodology ◽  
Heat Transfer Performance ◽  
Transmission Loss ◽  
Design Parameters ◽  
Transfer Performance ◽  
Noise Mitigation ◽  
Acoustic Cavity ◽  
Road Map ◽  
Noise Barrier

In this article, we have first presented a metasurface design methodology by coupling the acoustic cavity to the coiled channel. The geometrical design parameters in this structure are subsequently studied both analytically and numerically to identify a road map for silencer design. Next, upon tuning the design parameters, we have introduced an air-permeable noise barrier capable of sound silencing in the ultrawide band of the frequency. It is has been shown that the presented metasurface can achieve +10 dB sound transmission loss from 170 Hz to 1330 Hz (≈3 octaves). Furthermore, we have numerically studied the ventilation and heat transfer performance of the designed metasurface. Enabling noise mitigation by leveraging the proposed metasurface opens up new possibilities ranging from residential and office noise reduction to enabling ultralow noise fan, propellers, and machinery.

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