The Influence Of Variable Geometry Parameters On A Miniature Centrifugal Compressor

At present,the global demand for energy is changing.People pay more attention to the protection of the environment.At the same time,the power system has received more attention,and the microturbine has received more attention because of its own characteristics.The design of the high-speed,high-pressure centrifugal compressor,which is one of the core components of the microturbine,plays a decisive role in the design system of the microturbine.Understanding the flow mechanism of the centrifugal compressor and improving the performance of the compressor has become a research hotspot.In this paper,numerical simulation of a 100 kW high speed,high pressure ratio centrifugal compressor.Completing the grid independence verification and determine the number of single-channel grids.Numerical simulating the centrifugal compressor at different speeds,drawning the characteristic curve of the centrifugal compressor and analyze the performance and internal flow flied of the centrifugal compressor.Exploring the factors that affect the performance of high-speed,high-pressure ratio centrifugal compressor.The internal flow of the centrifugal compressor changing to analyze the influence of shock waves,leakage flow on the flow field,and master the characteristics of the internal flow field of the centrifugal compressor.In this paper,a large number of numerical calculations performe on the designed centrifugal compressor.Discussing the effects of changing the number of blades,increasing the thickness of the blades on the overall performance of the centrifugal impeller such as flow rate,pressure ratio and efficiency.Analyzing changechanges in the internal flow of the centrifugal compressor after the parameters change,and summe up the influence rules.Obtain the number of different blades and different blade thickness entrifugal compressor performance and provide a basis for further optimization of the centrifugal compressor.Numerical simulation of centrifugal compressors with tip clearances of 0.2mm,0.4mm,0.6mm and 0.8mm to study their effects on compressor performance and flow field.Comparing the performance curves under different clearance conditions,founding that compressor with good work performance,high adiabatic efficiency and high total pressure ratioin in 0.2mm and 0.4mm gap size,.When the rotor’s shroud gap increases to 0.06 cm or 0.08 cm,the tendency of streamline climbing over the tip from pressure side to the suction side is strengthened.The loss of tip leakage is enlarged,the performance of compressor is deteriorated,the range of mass flow decreases.The research results of this dissertation show that complex flows in the high-speed,high-pressure ratio centrifugal compressors.Through changing the number of blades,the thickness of the blades and the size of the tip clearance,the effect on the performance of the compressor is very significant.Providing helps to improve the design of the centrifugal compressor performance.