Researcher: Royce Fernandes Title: Investigation of Pin Fin Cooling Channels for Applications in Gas Turbines Institution: Embry-Riddle Aeronautical University Degree: Master of Science in Aerospace Engineering Year: 2016 Gas turbine blades are often cooled using internal cooling channels to prevent failure at temperatures beyond material limitations. Pin fin channels are commonly used on the t...

In this paper, convection heat transfer of Al2O3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. For each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. The governing equations in...

Abstract   Due to restrictions on the choice of relaxation time in single relaxation time (SRT) models, simulation of flows is generally limited base on this method. In this paper, the SRT lattice Boltzmann equation was used to simulate lid driven cavity flow at different Reynolds numbers (100-5000) and three aspect ratios, K=1, 1.5 and 4. The point which is vital in convergence of this scheme ...

We extend the Kolmogorov phenomenology for the scaling of energy spectra in high-Reynolds-number turbulence, to explicitly include the effect of helicity. There exists a time scale tau(H) for helicity transfer in homogeneous, isotropic turbulence with helicity. We arrive at this time scale using the phenomenological arguments used by Kraichnan to derive the time scale tau(E) for energy transfer...

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...

Numerical simulation of the turbulent flow around a triangular cylinder at Reynolds number of 45,000 is presented in this paper. A body force potential model is used to model the turbulent motion. This approach is able to model non-equilibrium turbulence accurately at a cost and complexity comparable to k-ε models. The numerical method used in this calculation is an unstructured staggered mesh ...

The similarity form of the scalar-variance spectrum at high Schmidt numbers is investigated for nonstationary turbulence. Theoretical arguments show that Batchelor scaling may apply only at high Reynolds numbers. At low Reynolds numbers, Batchlor scaling is not possible unless the turbulence is stationary or the enstrophy decays asymptotically as t. When this latter condition is satisfied, it i...