A new method to measure vehicle pass-by noise in a finite dimensioned semi-anechoic room

Arslan, Ersen
In this study, a method to predict vehicle pass-by noise in a finite dimensioned, semi-anechoic chamber with chassis dynamometer has been developed. Vehicle noise has been modeled as the summation of the individual contributions regarding the principal noise components, namely, engine including air intake, front tire and rear tire noises. This method employs wave propagation, Doppler shift, and time delay in the estimation of the sound pressure due to each component at points of interest specified by relevant standards. An acoustical simulation model has been developed in MaTLAB environment. The model has been applied on two different vehicles. Finally, the predicted sound pressure values are found to be in good agreement with the corresponding values acquired in outdoor measurements addressed in ISO 362 for vehicle pass-by noise measurement standard.


A computer simulation of void dynamics under the action of electromigration and capillary forces in narrow thin interconnects
Ogurtani, TO; Oren, EE (2000-10-25)
In these studies a comprehensive picture of void dynamics in connection with the critical morphological evaluation has been thoroughly anticipated in order to understand main reasons as well as the conditions under which premature failure of metallic thin interconnects occur. Our mathematical model on diffusion and mass accumulation on void surfaces, under the action of applied electrostatic potential and capillary effects, follows a novel irreversible but discrete thermodynamic formulation of interphases a...
Optimization of ride comfort for vehicles equipped with passive and active hydro-pneumatic suspensions
Sağlam, Ferhat; Ünlüsoy, Yavuz Samim; Department of Mechanical Engineering (2016)
The main objective of this study is the optimization of ride comfort performance of vehicles equipped with Hydro-Pneumatic (HP) suspension systems. In order to improve ride comfort performance together with handling behavior as a constraint, active-passive, and unconnected-interconnected HP suspension systems are included in the study. The basic HP suspension model is developed and validated by experiments. Various HP suspension systems of increasing complexity are modeled, and their dynamic characteristics...
Analysis of flexible pavements incorporating nonlinear resilient behavior of unbound granular layers
Karagöz, Cem; Acar, Soner Osman; Department of Civil Engineering (2004)
Traditionally, the resilient modulus values obtained from repeated unconfined or triaxial compression tests are used as the elastic modulus of granular layers in structural analysis of flexible pavements. Sometimes the resilient modulus of granular materials are estimated from known California bearing ratios (CBR) or stabilometer resistance (R) values by simple regression equations. On the other hand, it is well known that stress-strain relation for unbound granular materials is nonlinear and the resilient ...
A Two stage approach for hybrid-assembly line design
Şimşek, Doğukan; Kırca, Ömer; Department of Industrial Engineering (2014)
The aim of the study is to propose an approach for hybrid assembly line design in the make-to-order and mixed-model environment. In this context, the main goal is to reduce lead-time, which is one of the key concepts of competitive markets. A systematic approach was employed for designing of hybrid assembly line in order to achieve the goal. The line is divided into two parts in a hybrid system: while the first part of the line works as a closed-loop system for instant replenishment of Constant Work in Prog...
Computation of drag force on single and close-following vehicles
Örselli, Erdem; Çetinkaya, Tahsin Ali; Department of Mechanical Engineering (2006)
In this study, application of computational fluid dynamics to ground vehicle aerodynamics was investigated. Two types of vehicle models namely, Ahmed Body and MIRA Notchback Body and their scaled models were used. A commercial software "Fluent" was used and the effects of implementing different turbulence models with wall functions were observed. As a result, an appropriate turbulence model was selected to use in the study. The drag forces, surface pressure distributions and wake formations were investigate...
Citation Formats
E. Arslan, “A new method to measure vehicle pass-by noise in a finite dimensioned semi-anechoic room,” M.S. - Master of Science, Middle East Technical University, 2010.