The unsteady discrete adjoint equations are utilized to construct objective function gradients for use in geometry optimization in large scale three-dimensional unsteady ow problems. An existing massively parallel unstructured Reynolds-averaged Navier-Stokes equations solver forms the basis for the framework used to solve both the primal and dual (adjoint) problems. The framework is also capabl...

The intent of shielding functions in delayed detached-eddy simulation methods (DDES) is to preserve the wall boundary layers as Reynolds-averaged Navier–Strokes (RANS) mode, avoiding possible modeled stress depletion (MSD) or even unphysical separation due to grid refinement. An entropy function f s is introduced to construct a DDES formulation for the k-ω shear stress transport (SST) model, wh...

In this paper, the low-speed aerodynamic performance of lambda wing with a chord length c=210 mm and sweep angle Λ =51°, thickness 3 mm, beveled leading edges on windward side an 58° is investigated numerically. Reynolds Average Navier Stokes (RANS) theorem equations Spalart-Allmaras turbulence model were solved up to attack 45° for incompressible flow around surface and, are compared experimen...

Numerical simulations based on a high-order discontinuous Galerkin solver were performed to investigate two-dimensional flapping foils at moderate Reynolds numbers, moving with different prescribed harmonic motion laws. A Spalart–Allmaras RANS model and without an algebraic local transition modification was employed for the resolution of multiple kinematic configurations, considering both moder...

The aerodynamic performance of the high-lift configuration greatly influences safety and economy commercial aircraft. Accurately predicting configuration, especially stall behavior, is important for aircraft design. However, complex flow phenomena configurations pose substantial difficulties to current turbulence models. In this paper, a three-equation k-(v^2)-{\omega} model Reynolds-averaged N...

A time-dependent numerical simulation is performed to examine the flow separation control with action of a hybrid jet (the combination synthetic and continuous jets) over NACA23012 airfoil. The unsteady Reynolds-averaged Navier–Stokes (URANS) Spalart-Allmaras (SA) turbulence model simulate field around airfoil analyse effect jet. combined placed at point on upper surface which located 12% chord...

An adjoint-based Navier–Stokes design and optimization method for two-dimensional multi-element high-lift configurations is derived and presented. The compressible Reynolds-averaged Navier–Stokes equations are used as a flow model together with the Spalart–Allmaras turbulence model to account for high Reynolds number effects. When a viscous continuous adjoint formulation is used, the necessary ...

The air layer formation in a high Reynolds-number flat plate turbulent boundary layer is simulated using a two-phase sharp interface Cartesian grid solver. The interface is tracked by a coupled level set and volume-of-fluid method (CLSVOF) and turbulence is modeled by a Spalart-Allmaras (SA) turbulence model with a wall function (WF) approach. The air layer along the entire test plate is succes...

Adaptive morphing trailing edge wings have the potential to reduce the fuel burn of transport aircraft. In this paper, we quantify the aerodynamic performance benefits of a morphing trailing using aerodynamic design optimization. The aerodynamic model solves the Reynolds-averaged Navier– Stokes equations with a Spalart–Allmaras turbulence model. A gradient-based optimization algorithm is used i...