Conjugate Heat Transfer Analysis for a Film-Cooled Turbine Vane

Abstract

A conjugate heat transfer analysis methodology has been defined and applied to an Air Force film cooled turbine vane consisting of 648 cooling holes. An unstructured computational mesh was used to model both the fluid and metal sides of the turbine vane. A summary of the numerical methods employed by Code Leo is provided along with a description of the coupling procedure employed between the fluid and heat conduction computations. Numerical simulations were conducted at multiple mesh resolutions to assess accuracy and repeatability. A detailed review is presented for the numerical solution obtained from a fine mesh consisting of 24 million elements (8 million solid, 16 million fluid) covering all 648 film holes. Results showed that cooled air from the film holes formed a protective layer around the airfoil surfaces and endwalls as intended. Low metal temperatures were present not only on the external surfaces exposed to hot gas, but also around the entrances to the film cooling holes. Cooled air was also observed to pile up along the pressure surface at mid-span. Solution convergence was achieved in approximately 15,000 iterations and 100 hours elapsed time on a dual-socket Intel E5504 workstation. The combination of fast turnaround time with accurate metal temperature prediction will enable conjugate heat transfer analysis to be easily incorporated into routine design processes to better address durability goals.

Numerical Study of the Effects of Thermal Barrier Coating and Turbulence Intensity on Cooling Performances of a Nozzle Guide Vane

“…Recently, CHT analysis has been commonly applied to predict the real metal surface temperatures and cooling performances of turbine vanes. In the numerical investigations of previous works [15][16][17][18], CHT analysis was used to study the film cooled vanes without TBC. Using a Mark II vane provided by Hylton et al [19], Bohn and Becker [20] used 3D CHT analysis and a BaldwinLomax turbulence model [21] to study the aerodynamic and thermal effects of the vane without and with TBC (ZrO2, 0.3 mm thickness).…”

Modelling of heat transfer and fluid flow in the hot section of gas turbines used in power generation: A comprehensive survey

“…The present study deals with the heat transfer and fluid flow models of hot section technology relevant to gas turbines in power generation. Conjugate heat transfer models, unsteady convective models, unsteady convective models (with time‐averaged and time‐dependent parameters), and reduced order lumped capacitance thermal network method are discussed in detail under first principle modelling . Basically, first principle modelling is conducted by analysing the physical relationships of heat transfer and thermodynamics.…”

Geometry/Grid Generation for 3D Multi-Disciplinary Simulations in Multi-Stage Turbomachinery

“…Dawes et al [6][7][8] developed an automated, unstructured-grid generation procedure using an octree-based cut-Cartesian method with a level-set geometry representation. Ni et al 9 demonstrated an unstructured-grid octree grid generation approach for turbine conjugate heat transfer simulation. For non-linear fluid/structure interaction applications of compressors, Ramakrishnan et al 10 , Gottfried and Fleeter 11 , and Im and Zha 12 used simple algebraically generated grids for the solid airfoils that were point-matched to multi-block grids for the passage flow.…”