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Simulation Study On Fluid-Structure Coupling Of Micro Centrifugal Compressor Impeller

Posted on:2020-02-19Degree:MasterType:Thesis
Country:ChinaCandidate:L L HanFull Text:PDF
GTID:2382330575454565Subject:Chemical Process Equipment
Abstract/Summary:PDF Full Text Request
The microturbine engine,a small power equipment which is of its strategic importance,has been the key points of research in various countries.The compressor is a core component of the micro-turbine engine.And the impeller as the only component which does work inside the compressor determines the performance of the compressor,so as to have influence on the performance of the turbine engine.It is of great significance to implement numerical simulation and finite element analysis of impeller strength for improving the performance of the micro-compressor under high temperature,high pressure and high speed as well as complex multi-phase coupling environment.The thesis contains the following work:(1)Numerical simulation of a micro turbine engine compressor impeller is employed by using the engineering software ANSYS CFX,and the flow distribution of the characteristic section of the compressor impeller is analyzed.And the influence of the number of blades and the length of the splitter blade on the performance of the compressor impeller is investigated based on the analysis of the internal flow field.It shows that the optimal number of blades of the impeller is 7 pairs,and the optimal length of the impeller is the 0.813 times length of the main blade.While the compressor pressurization ratio is 3.81 and the isentropic efficiency is 66.82%.(2)The unidirectional fluid-solid coupling simulation of the impeller blades is developed in order to get the stress-strain distribution of the impeller blades.The stress-strain distribution of the impeller blades under the fluid-solid coupling is analyzed,as a result,the stress distribution cloud diagram of the impeller blades is acquired.Besides,the effects of centrifugal force and aerodynamic force on the stress and strain of the impeller blades are compared,which suggests that the maximum stress of the impeller blade occured at the root of the blade is 705.33 MPa.And the maximum strain developd at the tip of the blade leading edge is 0.28 mm.Meanwhile,the natural frequency and mode shape of the impeller under prestressed and prestressed conditions are analyzed which turns out that stress increases the stiffness and natural frequency of the impeller.(3)Finally,the influence of thermal load on the impeller blade strength and natural frequency is considered,and centrifugal force,aerodynamic force and thermal load are applied to the impeller blades.The stress and strain distribution of the impeller blades under the combined action of three forces is worked out in the end.As a result,the maximum stress is increased by 7.62%,the maximum strain is increased by 26.32% and the thermal load makes the natural frequency increased after loading the thermal load,at the circumstance of only considering the centrifugal force and aerodynamic effects.
Keywords/Search Tags:centrifugal compressor, impeller, splitter blade, fluid-solid coupling, stress, strain, thermal load
PDF Full Text Request
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