Through Flow Analysis
 

Hi,

What is through flow analysis for turbomachines. Please enlighten on it and provide some references if possible.

Thanks Apurva

Re: Through Flow Analysis
 

Hello Apurva,

A Throughflow analysis is an axi-symmetric meridional analysis of a single blade or multi-stage turbomachinery configuration, where the presence of the blades is taken into account through source terms : - the turning induced by the blade; - the blockage of the blade; - the blockage of the boundary layer (along the blades and the endwalls).

Correlations are used to estimate the losses.

Throughflow methods can generally be used either in analysis mode (information on the exit flow angle is imposed, the tangential velocity is computed) or in design mode (vice-versa).

Throughflow methods are widely used in large turbomachinery industry to make the first design of multi-stage machines (e.g. aero-engines, large industrial compressors and gas turbines,...). As this is a 2D problem, it runs pretty fast ( a few seconds to a few minutes) compared to a 3D inviscid or viscous calculation, but of course it is less accurate and you can not get any detail about the flow field.

There are two families of Throughflow codes : the most popular one is based on an approximate 'streamline curvature' approach. The second method is based on the 2D axisymmetric Euler equations.

In NUMECA, we have decided to implement this second method, because we believe that it offers some advantages. The first one is that you can easily couple Throughflow blocks with 3D ones, as the code is basically the same as a classical 3D solver. The second advantage is that there is no problem to get converged transonic solutions, which is usually very tricky with a streamline curvature method.

For your information, here is the reference of an article which describes this Euler Throughflow method :

A. STURMAYR & CH. HIRSCH (1999). 'ThroughFlow model for design and analysis integrated in a three-dimensional Navier-Stokes solver'. Presented at the 3rd European Turbomachinery Conference, London, 1999.

Kind regards,

Bruno

inquiry
 

Hello, Bruno
I wonder that if you are working on throughflow analysis right now?
I want to ask you something about the second method you mentioned above.