The effect of dense gas dynamics on loss in ORC transonic turbines

1st International Seminar on Non-Ideal Compressible-Fluid Dynamics for Propulsion & Power

物理学;力学

Durá Galiana, F.J.^1 ; Wheeler, A.P.S.^2 ; Ong, J.^3 ; De Ventura, C.A.M.^2

Aerodynamics and Flight Mechanics, Engineering and the Environment, University of Southampton, Southampton

SO17 1B, United Kingdom^1

Whittle Laboratory, Department of Engineering, Cambridge University, Cambridge, United Kingdom^2

GE Global Research, Munich, Germany^3

关键词: CFD simulations;    Computational studies;    Detached eddy simulations;    Measurements of;    Modelling method;    Spatial and temporal resolutions;    Supersonic base flow;    Transonic turbine;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/821/1/012021/pdf
DOI  :  10.1088/1742-6596/821/1/012021

学科分类：力学，机械学

来源: IOP

【 摘 要 】

This paper describes a number of recent investigations into the effect of dense gas dynamics on ORC transonic turbine performance. We describe a combination of experimental, analytical and computational studies which are used to determine how, in-particular, trailing-edge loss changes with choice of working fluid. A Ludwieg tube transient wind-tunnel is used to simulate a supersonic base flow which mimics an ORC turbine vane trailing-edge flow. Experimental measurements of wake profiles and trailing-edge base pressure with different working fluids are used to validate high-order CFD simulations. In order to capture the correct mixing in the base region, Large-Eddy Simulations (LES) are performed and verified against the experimental data by comparing the LES with different spatial and temporal resolutions. RANS and Detached-Eddy Simulation (DES) are also compared with experimental data. The effect of different modelling methods and working fluid on mixed-out loss is then determined. Current results point at LES predicting the closest agreement with experimental results, and dense gas effects are consistently predicted to increase loss.