Research On The Design And Performance Prediction Method Of Helium-Xenon Hybrid Radial Turbine

Helium xenon radial turbine is a hot topic in the field of turbomachinery.Helium xenon mixture,as a new type of mixed working fluid,plays an important role in the development of helium xenon radial turbines.In recent years,researchers have continuously studied the mechanism of the influence of helium xenon mixture on the performance of radial flow turbines through numerical simulation,experimental analysis,and other means,aiming to improve its efficiency and reliability,thereby promoting the progress of turbine technology.At present,there is relatively little research on the design method and performance prediction of a helium xenon mixture based radial turbine.Therefore,this article has conducted relevant research on helium xenon radial turbines.Firstly,this article conducted in-depth research on helium xenon mixture.Based on Chapman-Enskog theory and corresponding state law,a physical property calculation program for helium xenon mixture was developed.The calculation results of the physical property calculation program were compared with relevant experimental data,and the results showed that the relative error between the two met the design requirements.The physical property calculation program can accurately estimate the physical properties of helium xenon mixture.Based on this physical property calculation program,the flow characteristics of a 40g/mol helium xenon mixture in a radial turbine and its impact on the performance of the turbine were studied.Based on the design method and parameter selection principles of the radial turbine,the aerodynamic design of the helium xenon radial turbine was carried out,and the initial design parameters of the helium xenon radial turbine were determined to obtain the turbine design plan.Numerical simulation research was conducted on helium xenon radial turbines,analyzing their performance under design and variable operating conditions.The changes in efficiency of helium xenon radial turbines under different temperature,speed,and mass flow conditions,as well as the distribution of pressure,temperature,speed,and Mach number at different blade heights,were understood.Secondly,based on the theory of working fluid substitution,the characteristic calculations of air replacing helium xenon mixture in the same radial turbine were completed,and the characteristic curves and distribution patterns of air radial turbine and helium xenon radial turbine under similar conditions were compared and analyzed.The results show that under the similar conditions of Mach number,Reynolds number and so on,the calculation results of the air run off turbine are basically the same as those of the helium xenon run off turbine.Finally,based on the one-dimensional characteristic calculation method,a program for predicting the one-dimensional characteristics of a radial turbine considering the characteristics of helium xenon mixture was developed.Due to the lack of a loss model for helium xenon mixture,the loss models used in the estimation program are all applicable to air.Therefore,the working fluid substitution theory is used to modify the loss model.The one-dimensional characteristic estimation program after using the modified loss model was used to estimate the characteristics of a helium xenon radial turbine.Under design conditions,the relative error between the corrected program calculation results and the three-dimensional calculation results was 0.82% for the total-total temperature ratio,4.29% for the total-total expansion ratio,and 1.94% for the efficiency.The relative error between the corrected program estimation and the three-dimensional calculation was reduced compared to the error before the correction,Further improved the accuracy of the one-dimensional characteristic calculation program.