Three dimensional simulation of the flow
in a boundary layer turbine
Yingya Zhou
Dept.Thermal Engineering, Tsinghua University, China
Abstract
A three-dimensional flow in a boundary layer turbine is simulated using commercial CFD software. The computation results are compared with experimental results of the same turbine. The simulation explains the air leakage and low efficiency problems in the experimental turbine and confirms that the turbine suffers from large exhaust loss and suggests that the nozzle inlet pressure should be reduced and rotor seals are worth improving to enhance the efficiency of the experimental turbine.
Keyword boundary layer turbine, CFD
Introduction
The boundary layer turbine is an unconventional bladeless turbine first patented by Nikola Tesla in 1913[1]. It is also referred to as the Tesla turbine, multiple-disk turbine, friction turbine, shear-force turbine and co-rotating disk turbine.
The boundary layer turbine rotor is comprised by parallel disks. The momentum exchange between the fluid and the rotor is via adhesion rather than impingement as in conventional bladed turbines. Therefore, the boundary layer turbine is simple to manufacture and capable of handling a wide range of fluids. However, the boundary layer turbine has long been ignored owing to the development of bladed turbines and lack of applications in early times. There has been only limited number of analytical and experimental investigations on the boundary layer turbine. Even fewer studies combined the experimental results with theoretical analyses of the same turbine.
This study presents a three dimensional CFD simulation of the flow in the boundary layer turbine. The geometry and operation conditions were according to Beans’ experiment[2] . Computational results are compared with experimental results.
Model setup
Geometry
The experiment turbine geometry is shown in [ Fig. 1 ]. The simulation model geometry was made according to the experimental...