A comparison of block preconditioners for isogeometric analysis discretizations of the incompressible Navier–Stokes equations

We deal with numerical solution of the incompressible Navier–Stokes equations discretized using the isogeometric analysis (IgA) approach. Similarly to finite elements, the discretization leads to sparse nonsymmetric saddle-point linear systems. The IgA discretization basis has several specific properties different from standard FEM basis,...

Numerical Simulation of Flow over an Axisymmetric body in Free Flight

Flow field around a projectile after thrust has been stopped and in inertia flight is studied numerically by a finite difference scheme. This study aims at clarifying the mechanism of free flight, which is generated and developed by rotation of body and gravity. Among two types of projectiles concerned a three-dimensional flow around the slender...

ILES and LES of Complex Engineering Turbulent Flows

The present study concerns the application of Large Eddy Simulation (LES) and Implicit LES (ILES) to engineering flow problems. Such applications are often very complicated, involving both complex geometries and complex physics, such as turbulence, chemical reactions, phase changes and compressibility. The aim of the study is to illustrate what...

Prediction of flow-induced noise using the expansion about incompressible flow approach

In the present paper an Expansion about Incompressible Flow approach, as suggested by Shen and Sørensen1, will be used and discussed for the simulation of flow-induced sound at low Mach numbers. The method consists of two parts: First solving for the incompressible, viscous flow field, and second computing the fluctuating acoustic field. As a...

A high-order discontinuous Galerkin method for natural convection problems

Discontinuous Galerkin (DG) methods have proved to be very well suited for the construction of robust high-order numerical schemes on unstructured and possibly non conforming grids for a wide variety of problems. In this paper we consider natural convection flow problems and present a high-order DG method for their numerical solution. The...

Stabilized FEM for incompressible flow: A critical review and new trends

The numerical solution of the nonstationary, incompressible Navier-Stokes model can be split into linearized auxiliary problems of Oseen type. We present in a unique way different stabilization techniques of finite element schemes on isotropic and hybrid meshes. First we describe the state-of-the-art for the classical residual-based SUPG/PSPG...

A three-dimensional finite volume method for incompressible Navier-Stokes equations on unstructured hybrid staggered grids

In this work, a new method was described for spatial discretization of threedimensional Navier Stokes equations in their primitive form, on unstructured, staggered grids. Velocities were placed on the cell faces and pressure in cell centers and were linked with the projection method. Thanks to the variable arrangement, no stabilization procedure...

ARSPNS: a method to calculate steady and unsteady potential flow about fixed and rotating lifting and nonlifting bodies

A new method ARNSPNS is described for the calculation of steady and time-linearized unsteady incompressible potential flow about arbitrary lifting and nonlifting bodies in an arbitrary mean steady flow field, including rotation. The method belongs to the category of the so-called panel methods. Applications have been made to wind turbines...

Two-dimensional modelling of capillary liquid flow in a thin annulus

One of the experiments performed on board Spacelab, involves a partially filled annular cylinder which is subjected to prescribed motions (Ref. 1). The interest in this configuration arises from its practical use; for instance, the coolant in IRAS was stored in an annulus-like tank. In this report, a mathematical model for the transient liquid...

A system for computer aided analysis and design of multi-element airfoils

A program system has been developed as a tool for interactive analysis and design of multi-element airfoils in incompressible viscous flow. A global description of the system is given. It involves the application of three computational methods, one for the analysis of viscous flow and one for the analysis of inviscid flow around multi-element...

Evaluation of Thing's method for the calculation of the lift discription on a wing in propulsive jets

The calculation method presented by Ting, Liu and Kleinstein in reference 3 has been subjected to an evaluation study, principally on the basis of experimental data obtained from special experiments on a half wing immersed in two jets. Very satisfactory results were found for the unflapped wing lying centrally within the jets. Both flap...

Finite difference calculation of incompressible flow through a straight channel of varying rectangular cross section, with application to low speed wind tunnels

A fully-conservative- finite difference algorithm is described to calculate the incompressible flow through a straight channel of varying rectangular cross section. Both the width and the height of the channel may vary independently. The algorithm has been used successfully in the design of the German-Dutch low speed wind tionel (DNW).

Calculation of the flow around a swept wing, taking into account the effect of the three-dimensional boundary layer. Part II: Wing with laminar boundary layer on the lower surface

The attached flow around a swept wing has been calcTilated with allowance for the effects of boundary layer and wake. In part I a swept wing was considered with a turbulent boundary layer on both the upper and lower wing surface. The present part of the study deals with the calculation of the flow around the same swept wing with a laminar...

A simple finite-difference technique for the computation of three-dimensional incompressible laminar boundary layers. Part I: Description of the method

This report consists of two parts. The first part describes a finite-difference scheme for the computation of 3D laminar boundary layers over developable surfaces. The stability of the first variation of the difference scheme is investigated. Some results of actual boundary-layer calculations are presented for flows over swept wings. The second...

Airfoil design by the method of singularities via parametric optimization of a geometrically constrained least squares object function

The present report describes a method for the design of airfoils in incompressible flow which, subject to geometrical constraints generate approximately a given distribution of the pressure coefficient along the projection of the airfoil chord on an axis parallel to the onset flow. The flow is simulated by means of a distribution of...

The law of the wall in two- and three- dimensional turbulent boundary layers

The law of the wall has been extended to three-dimensional flows, The effects of both the pressure gradient and the inertial forces have been considered. The deduced wall law is valid when the deviations from the simple two-dimensional law of the wall are small. Agreement with measurements is found within the possible experimental error.

Measurements in a three-dimensional incompressible turbulent boundary layer in an adverse pressure gradient under infinite swept wing conditions

On a wind tunnel model, especially designed to check calculation methods, measurements were made of a three-dimensional turbulent boundary layer under infinite swept wing conditions in an adverse pressure gradient, with a three-dimensional separation near the trailing edge. Accurate measurements of the external flow field, the mean velocity...