There are a number of systems in which supercritical cryogenic fluids are used as coolants or propellant fluids. In some modern military aircraft, the fuel is pressurized above its critical point and used as a coolant to remove heat from the aircraft engine. Accurate prediction of heat transfer coefficients to turbulent flows of supercritical fluids is essential in design of such systems. One o...

The underexpanded microjet emerging from a rectangular convergent nozzle with high aspect ratio at the exit is investigated numerically using Reynolds-averaged Navier-Stokes (RANS) simulation Menter’s shear stress transport (SST) k-ω turbulence model. performed pressure of 5.0 to produce strong shock and it validated by comparison rainbow schlieren picture microjet. three-dimensional structure ...

The purpose of this study was to determine the total resistance and investigate flow around a full-scale kayak. Utilizing Computational Fluid Dynamics(CFD), it deter-mined how presence rudder affects kayak hydrodynamic performance. To an-alyse flow, computational fluid dynamics based on RANS-VOF solver em-ployed. volume approach k-ω turbulence model were used in two-phase steady simulations hul...

Abstract The accuracy of wind flow simulation in mountain area micro-topography is related to discrete scheme, turbulence model and wall function. In this paper, the standard hill adopt analyze calculation different models. Four models, including RNG k-ε, k-ω , SST TSST were used calculation, compared with result tunnel test. results second-order upwind or scalable function are basically consis...

Four classes of turbulence models (algebraic, k − , k − ω and a differential Reynolds-stress model) are applied to boundary layers under adverse pressure gradient with a constant equilibrium parameter β = δ * τ w dp dx. Numerical solutions up to Re θ = 10 8 give the classical scalings in the inner and outer layer for all models. Comparison is made with experiments of Clauser at β ≈ 2 and 8 and ...

to enhance the understanding of the impact of obstacle buildings on pollution transportationand dispersion in the atmospheric boundary layer, it is necessary to know the atmospheric flow characteristics over terrains. wind flow characteristics in a boundary layer over a step-shaped cliff topography model with rough and smooth surfaces were studied numerically using computational fluid dynamics ...

In this work, we try to find the best setting of Computational Fluid Dynamic solver available for the problems in the field of supersonic internal flows. We used the supersonic air-toair ejector to represent the typical problem in focus. There are multiple oblique shock waves, shear layers, boundary layers and normal shock interacting in the supersonic ejector making this device typical in fiel...

Lattice Boltzmann method (LBM) has become an alternative method of computing a variety of fluid flows, ranging from low Reynolds number laminar flows to highly turbulent flows. For turbulent flows, non-uniform grids are preferred. Taylor series expansionand least-squares-based LBM (TLLBM) is an effective and convenient way to extend standard LBM to be used on arbitrary meshes. In order to show ...

The flow structure of strongly turbulent Taylor-Couette flow with Reynolds numbers up to Re(i)=2×10(6) of the inner cylinder is experimentally examined with high-speed particle image velocimetry (PIV). The wind Reynolds numbers Re(w) of the turbulent Taylor-vortex flow is found to scale as Re(w)∝Ta(1/2), exactly as predicted by Grossmann and Lohse [Phys. Fluids 23, 045108 (2011).] for the ultim...