Acoustical analysis of exhaust mufflers for earth-moving machinery

Olğar, Tarık
This study concerns with acoustical analysis of exhaust mufflers for earth-moving machinery. The study arises from the fact that there is a need for further noise reduction emitted by earth-moving machinery produced by Hidromek Inc. in order to be on the safe side of the limits stated in European Noise Directive 2000/14/EC. The acoustical performance of the muffler is investigated both experimental and numerical means. A three-dimensional finite element method is performed to calculate the transmission loss. An experimental setup is also developed to measure the transmission loss. Chung-Blaser, two-source and two-load methods are applied to measure the transmission loss of single expansion chamber with extended inlet/outlet. The experimental setup is verified by comparing the test results obtained by two-load method with one-dimensional analytical solution obtained by transfer matrix method. Transmission loss of the muffler of interest, calculated by finite element method is compared with the experimental results. Sound power level of earth-moving machinery and insertion loss of the muffler is measured to investigate the acoustical performance of the muffler. These results can then be served as guidance for the acoustical design of a muffler.


Modeling and experimental evaluation of variable speed pump and valve controlled hydraulic servo drives
Çalışkan, Hakan; Balkan, Raif Tuna; Department of Mechanical Engineering (2009)
In this thesis study, a valveless hydraulic servo system controlled by two pumps is investigated and its performance characteristics are compared with a conventional valve controlled system both experimentally and analytically. The two control techniques are applied on the position control of a single rod linear actuator. In the valve controlled system, the flow rate through the actuator is regulated with a servovalve; whereas in the pump controlled system, two variable speed pumps driven by servomotors reg...
Route planning for unmanned air vehicles
Tulum, Kamil; İder, S. Kemal; Department of Mechanical Engineering (2009)
In this thesis, automatic routing technologies for unmanned air vehicles are investigated. A route planner that minimizes the fuel consumption and maximizes the survivability is developed. While planning the route, using more than one objective entails the auto-routing problem to multi-objective optimization considerations. In this work, these considerations are handled with search algorithms. In order to assess the route options, a fuel consumption model and a survivability model are utilized for the route...
Design and performance evaluation of a fuel filter
Ayrancı, Hakan; Albayrak, Kahraman; Department of Mechanical Engineering (2010)
This thesis analyzes design criteria’s, performance evaluation of fuel filter. Fundamental concepts, definition and systems has been discussed at literature survey parts. Fundamentals of filter design tests and calculations are discussed. In Addition Frequency and amplitude effect on fuel filter efficiency investigated with different particle sizes by preparing special test set up. Test results has been analyzed by using Regression, Anova and Analyze of Variance methods with Minitab software.
Laboratory investigation of hydraulic efficiency of transverse grates in roads
Özbey, Cumhur; Tiğrek, Şahnaz; Department of Civil Engineering (2015)
In this study, hydraulic efficiency of transverse grated inlet systems to be used in small roads is experimentally investigated. For this purpose, an existing experimental setup in the Hydromechanics Laboratory of METU is utilized. Three sets of experiments are conducted in order to examine the relationship between the total flow rate and the grate efficiency with respect to several parameters. In the first set, the interdependence of the void ratio and grate efficiency is investigated. In the second set of...
Noise source identification and adoption of proper noise control strategies on wheeled tractors
Balaban, Murat; Çalışkan, Mehmet; Department of Mechanical Engineering (2010)
This thesis is aimed at identifying the noise sources of a wheeled tractor to reduce the noise levels below the legislative limits by controlling noise sources through proper methodologies. The study focuses firstly on identifying the noise sources of a wheeled tractor by using proper noise source identification techniques. These techniques can be summarized as sound intensity measurements, sound power level determination studies and spectral analysis of the noise data acquired in the tests. Simple sound in...
Citation Formats
T. Olğar, “Acoustical analysis of exhaust mufflers for earth-moving machinery,” M.S. - Master of Science, Middle East Technical University, 2009.