External Heat Transfer Predictions in Supersonic Turbines Using the Reynolds Averaged Navier-stokes Equations
نویسندگان
چکیده
External heat transfer predictions are performed for two-dimensional turbine blade cascades. The Reynolds averaged Navier-Stokes equations with algebraic (Baldwin-Lomax) and two-equation (low-Re k ?) turbulence closures are solved with an explicit Runge-Kutta time-marching nite volume method. Comparisons with measurement for subsonic and transonic cascades show good agreement in some cases, but also reveals problems with transition prediction and turbulence modeling. Stability, grid independence and problems in the stagnation point region are investigated. Blind simulations of a supersonic cascade are included to demonstrate the methods capability in handling this type of ows. Nomenclature cp Speciic heat J=kgK] C 1 , C 2 , C, k , Turbulence model constants ] D Turbulence model term J=kgs] E Turbulence model term J=kgs 2 ] e0 Total energy J=kg] f1, f2, f Damping functions ] k Turbulent kinetic energy J=kg] le Local equilibrium length scale m] p Static pressure Pa] P Production of k W=m 3 ] Pr Prandtl number ] qi Heat ux W=m 2 ] S Strain parameter ] T Static temperature K] ui Velocity m=s] yn Normal distance from the wall m] Dissipation of k J=kgs] ij Kronecker's delta function ] Speciic heat ratio ] Dynamic viscosity Ns=m 2 ] Density kg=m 3 ] S Extra Source Term, equation J=m 3 s 2 ] ij Shear stress tensor N=m 2 ] Vorticity parameter ] Subscript: t Turbulent contribution Superscript: lam Laminar part turb Turbulent part 0 Not an averaged quantity
منابع مشابه
Numerical investigations of turbulent natural convection heat transfer within a wind turbine nacelle operating in hot climate
The Algerian Sahara is characterized by severe climate conditions where temperature reaches high levels with large variations during day and season. Nacelles of wind turbines operating in this region are subjected to the overheating problem, in particular the electromechanical components becoming less effective as they heat up during use. In order to maintain an appropriate temperature of the a...
متن کاملFinite Volume Solution of a Cylinder in Cross Flow with Heat Transfer
A finite-volume model has been developed to study incompressible forced flow heat transfer of air over a circular cylinder in cross flow. An artificial compressibility technique is applied to couple the continuity to the momentum equations. The proposed explicit finite-volume method (FVM) uses a novel discretization in time and space. The governing equations are solved by time-marching using a ...
متن کاملAxi-symmetric Stagnation–Point Flow and Heat Transfer Obliquely Impinging on a Rotating Circular Cylinder
Laminar stagnation flow, axi-symmetrically yet obliquely impinging on a rotating circular cylinder, as well as its heat transfer is formulated as an exact solution of the Navier-Stokes equations. Rotational velocity of the cylinder is time-dependent while the surface transpiration is uniform and steady. The impinging stream is composed of a rotational axial flow superposed onto irrotational rad...
متن کاملNumerical Investigation of Conjugated Heat Transfer in a Channel with a Moving Depositing Front
This article presents numerical simulations of conjugated heat transfer in a fouled channel with a moving depositing front. The depositing front separating the fluid and the deposit layer is captured using the level-set method. Fluid flow is modeled by the incompressible Navier-Stokes equations. Numerical solution is performed on a fixed mesh using the finite volume method. The effects of Reyno...
متن کاملLarge-eddy/Reynolds-averaged Navier–Stokes simulation of a supersonic reacting wall jet
This work presents results from large-eddy/Reynolds-averaged Navier–Stokes (LES/RANS) simulations of the well-known Burrows–Kurkov supersonic reacting wall-jet experiment. Generally good agreement with experimental mole fraction, stagnation temperature, and Pitot pressure profiles is obtained for non-reactive mixing of the hydrogen jet with a non-vitiated air stream. A lifted flame, stabilized ...
متن کامل