Heat transfer analysis in internally-cooled fuel elements by means of a conformal mapping approach

1981 ◽  
Vol 67 (1) ◽  
pp. 101-108 ◽  
Author(s):  
G. Sánchez Sarmiento ◽  
P.A.A. Laura
Author(s):  
David L. Rigby ◽  
Jan Lepicovsky

This paper describes the addition of conjugate capability to an existing Navier-Stokes code. Also, results are presented for an internally cooled configuration. The code is currently referred to as the Glenn-HT code, because of its origin at the NASA Glenn Research center and its proven ability to predict flow and Heat Transfer. In the past, the code had been called traf3d.mb. The addition of the conjugate capability to the code was accomplished with a minimum amount of changes to the code, with the understanding that if more advanced techniques were required they could be added at a later date. In the solid region, the density is constant and the velocities are of course zero which leaves only a simplified form of the energy equation to be solved. This simplified energy equation is solved using the same method as in the gas regions with only minor changes to the numerical parameters. At the interface between the gas and solid the wall temperature is set so as to produce the same heat flux in each region. Results are presented for a pipe flow to validate the implementation. Numerical and experimental results are then presented for flow over a flat plate that is cooled internally. Flat plate Reynolds numbers in the range 180,000 to 950,000, and coolant channel Reynolds numbers in the range 30,000 to 60,000 are presented.


Author(s):  
Ilhan Gorgulu ◽  
Baris Gumusel ◽  
I. Sinan Akmandor

There are different characters of air flow in a conventional gas turbine blade cooling channel. These flow characters; including high streamline curvature caused from 180 degree bends, sequential flow separations caused from rib turbulators and pin-fin structures are analyzed separately with available commercial software for different turbulence models and validated against reliable experimental data from open literature. Also coupled conjugate heat transfer analyses on NASA C3X vane, which has only radial holes through blade span for cooling, are conducted with the same turbulence models. The accuracy information gathered from all these analyses; each interested with a single character of air and coupled conjugate heat transfer are put together and applied to a conjugate numerical analysis of internally cooled (VKI) LS-89 turbine blade. Internal cooling scheme which is applied to (VKI) LS-89 turbine blade encompassed the aforementioned flow characters and analyses are performed under realistic conditions. Because of the high temperature values occurring at realistic conditions, thermal conductivity and specific heat capacity of air and metal (Inconel 718) are modeled as temperature dependent material properties instead of using constant values. Conducted research revealed that 4 eqn. V2-f turbulence model gives similar results compared to the 2 eqn. Realizable k-e, k-w SST turbulence models for 180 degree bend and rib turbulator cases. However, at NASA C3X vane analyses V2-f turbulence model results are far more accurate than other two turbulence models in the manner of heat transfer coefficient and surface temperature distribution.


Sign in / Sign up

Export Citation Format

Share Document