Navier-Stokes Analysis of Turbine Blade Heat Transfer

Abstract

Comparisons with experimental heat transfer and surface pressures were made for seven turbine vane and blade geometries using a quasi-three-dimensional thin-layer Navier-Stokes analysis. Comparisons are made for cases with both separated and unseparated flow over a range of Reynolds numbers and freestream turbulence intensities. The analysis used a modified Baldwin-Lomax turbulent eddy viscosity model. Modifications were made to account for the effects of: 1) freestream turbulence on both transition and leading edge heat transfer; 2) strong favorable pressure gradients on re-laminarization; and 3) variable turbulent Prandtl number on heat transfer. In addition, the effect on heat transfer of the near-wall model of Deissler is compared with the Van Driest model.

Navier-Stokes analysis of radial turbine rotor performance

“…The mesh was refined near the blade surfaces and endwalls using hyperbolic tangent clustering. This clustering results in the nearest mesh node to the endwalls and blade surfaces being on the order of '1 =2.0 as recommended by Boyle [10].…”

Effect of Velocity and Temperature Distribution at the Hole Exit on Film Cooling of Turbine Blades

“…This calculation of eM due to free-stream turbulence was carried out only when the flow was laminar. Otherwise, the analysis would give significantly increased heat transfer for fully turbulent flow (Boyle, 1991 ). For the cases analyzed here, it implies that Forest's model is used only for the ACE rotor since for both the VK/ rotor and the C3X vane, the flow is turbulent at the leading edge itself due to the shower-head injection.…”

A k-omega turbulence model for quasi-three-dimensional turbomachinery flows

“…Although the low-Reynolds-number k-co model depends directly on Tu, in laminar regions the model gives values of turbulent viscosity that are much too small to affect the heat transfer. Boyle has added algebraic correlations to the BaldwinLomax model to simulate freestream turbulence effects [4]. These correlations could be added to the k-co code, but they do involve the distance from the wail.…”

“…These effects are sometimes added to the Baldwin-Lomax model using techniques developed for boundary layer codes [3,4]. Physical problems also include poor prediction of separation [5], which is important in compressors, and underprediction of wake spreading [2].…”