Search results for "Fluid Dynamic"
showing 10 items of 1034 documents
Shape design optimization in 2D aerodynamics using Genetic Algorithms on parallel computers
1996
Publisher Summary This chapter presents two Shape Optimization problems for two dimensional airfoil designs. The first one is a reconstruction problem for an airfoil when the velocity of the flow is known on the surface of airfoil. The second problem is to minimize the shock drag of an airfoil at transonic regime. The flow is modeled by the full potential equations. The discretization of the state equation is done using the finite element method and the resulting non-linear system of equations is solved by using a multi-grid method. The non-linear minimization process corresponding to the shape optimization problems are solved by a parallel implementation of a genetic algorithm (GA). Some n…
Optimal design for transonic flows
1991
The feasibility of finite element and mathematical programming methods for finding an optimal shape for an symmetric airfoil in case of transonic flow is studied. The state problem is solved using multigrid-technique. Numerical examples are given.
Influence of Confining Walls on the Dynamics of Supercooled Simple Liquids
2003
The relaxation dynamics of supercooled liquids in the bulk shows many features that are not seen in the dynamics of liquids at elevated temperatures, such as a very slow decay of the time-correlation functions, stretching, etc. The dynamics of liquids that are close to a surface (free space, confining wall, etc.) is even more complex in that the stretching is increased and in that there is evidence for the presence of multiple time scales. In this paper we review some results of recent molecular dynamics computer simulations in which we investigated the dynamics of a simple glass forming liquid in the vicinity of a wall. Two types of walls axe studied: A rough one and a smooth one. We find …
Two-Dimensional Boundary Layer Equations: High Resolution Capturing Methods
1993
In this paper we apply the piecewise hyperbolic and parabolic essentially non-oscillatory (ENO) capturing schemes (see [2] and [4]) to approximate the solution to the boundary layer equations for two-dimensional incompressible flow. We have tested several numerical examples analyzing their resolutive power and efficiency with respect to small values of the kinematic viscosity of the flow.
Thermal deformations of inhomogeneous elastic plates
1995
We consider thermal deformations of transversally inhomogenous elastic plates. Thin plate equations are derived as limits of full three-dimensional models both in the linear was well as in the non-linear case with appropriate convergence proofs. In the non-linear case also the corresponding von Karman equations are formulated. Its is obtained that the inhomogeneity leads to the loss of some symmetry properties at the von Karman equations
A Wind Tunnel Study of the Effects of Turbulence on the Growth of Cloud Drops by Collision and Coalescence
1999
A set of wind tunnel experiments was carried out to investigate the growth of single drops by collision coalescence with small droplets in laminar and turbulent flow. Analysis of the experiments shows that under otherwise similar conditions, there exists a tendency toward a faster drop growth under turbulence. The observed growth under laminar conditions agrees well with computed continuous growth of a collector drop using collision efficiencies reported in the literature.
Search for Scalar Bottom Quark Pair Production with the ATLAS Detector in pp Collisions at root s=7 TeV
2012
The results of a search for pair production of the scalar partners of bottom quarks in 2: 05 fb(-1) of pp collisions at root s = 7 TeV using the ATLAS experiment are reported. Scalar bottom quarks are searched for in events with large missing transverse momentum and two jets in the final state, where both jets are identified as originating from a bottom quark. In an R-parity conserving minimal supersymmetric scenario, assuming that the scalar bottom quark decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits are obtained in the (b) over tilde (1) ¿ (chi) over tilde (0)(1) mass plane such that for neutralino masses below 60 GeV scalar bottom masses up to …
Complex singularities and PDEs
2015
In this paper we give a review on the computational methods used to capture and characterize the complex singularities developed by some relevant PDEs. We begin by reviewing the classical singularity tracking method and give an example of application using the Burgers equation as a case study. This method is based on the analysis of the Fourier spectrum of the solution and it allows to determine and characterize the complex singularity closest to the real domain. We then introduce other methods generally used to detect the hidden singularities. In particular we show some applications of the Padé approximation, of the Kida method, and of Borel-Polya method. We apply these techniques to the s…
A modified least squares FE-method for ideal fluid flow problems
1982
A modified least squares FE-method suitable e.g. for calculating the ideal fluid flow is presented. It turns out to be essentially more efficient than the conventional least squares method. peerReviewed
Visualization 01.avi
2020
Rotating video of 3D cluster of bubbles.