Learning Forum

[AJMIT]

I performed steady-state CFD analysis (3D conjugate heat transfer analysis) of a gas turbine blade using Ansys CFX 2020 R1. The domain include hot gas domain, solid blade domain and cold gas domain (cooling channels). I used three turbulence model available in CFX in order to get best match with experimental values available on the mid span of blade (both pressure & suction side).

1. k epsilon Turbulence Model with scalable wall function (Default)

2. SST Turbulence Model with automatic wall function (Default)

3. SST Turbulence Model with automatic wall function and with Transitional turbulence Gamma-Theta.

These turbulence model calculate wall heat transfer coefficient based on turbulent wall function. I have gone through this page (https://www.cfd-online.com/Wiki/Ansys_FAQ) and also read other posts. I exported the results (Wall Heat Transfer Coefficient, Wall Adjacent temperature and Wall heat flux) in Microsoft Excel and then I used tbulk (bulk temperature) to calculate my new heat transfer coefficient (htc) as mentioned in the FAQ. When I calculate/plot heat transfer coefficient using 1st & 2nd turbulence model then the obtained values appears near the experimental values. Other Research paper shows similar trends. When I calculate/plot htc with 3rd turbulence model then the values changed too much. There is little change in Temperature distribution over mid span as compared to other two turbulence model. I have attached the images of plot for clear understanding.

HTC.jpg

[Swathi V. V.]

Hello As Ansys employees, we cannot download attachments. Please insert an image of the same.

[AJMIT]