In the automotive industry, especially in the heavy vehicles and diesel engines, turbocharger is used generally . Because of fluctuating nature of the diesel engine operation, the surge occurs for turbocharger compressor. This condition causes the efficiency to decreases and compressor instability to occur. So it is necessary to obtain performance curves and surge line by experiments. The purposes of this research are design and installation of heating turbocharger test stand to obtain and plot the performance curve of its centrifugal compressor. Then, the one-dimensional model of the compressor is developed and its results are compared with experiments. The test stand used for this work is a gas turbine unit in the Department of Mechanical Engineering thermodynamics lab that is equipped with a turbocharger at the exhaust. During this research, data logger system is improved from analog to digital, for more accurate and faster recording experimental data. Also data logger is able to support pressure, temperature and rotational speed simultaneously and the test data are monitored and stored in a computer. For this purpose a set of sensors available on the system are improved. Compressor performance curve (pressure ratio – mass flow rate and efficiency – mass flow rate) is obtained from the experiments which are in good agreement with the curves found according to the other references. Then, the one-dimensional modeling is done to predict the performance of centrifugal compressors. One-dimensional modeling is widely used to estimate the effect of geometric parameters changes on the overall performance of the compressor at design and off-design conditions. So having a reliable one-dimensional model is very important to reduce compressor experiment costs. In addition, this kind of model is very useful to predict the compressor performance when it operates as a part of multi-component system. It can also be used to match turbocharger components to integrate and optimize turbocharger-engine performance. The model estimates the compressor losses by some known theoretical – experimental relationships. For each compressor component, the program calculates the velocities, pressures, temperatures, pressure losses and efficiencies for a specified set of compressor geometry, atmospheric conditions, rotational speed, and fluid mass flow rate. Pressure ratio and efficiency versus mass flow rate and rotational speed are calculated at design and off-design conditions. Finally, the one-dimensional modeling results are compared with the experimental results which are in good agreement. Key word Test stand, Turbocharger, Centrifugal compressor, Performance curves, One-dimensional modeling, Performance prediction.
