BOUNDARY INTEGRAL SIMULATIONS OF THREE-DIMENSIONAL INVISCID FLOWS

Authors

  • RICARDO CAIADO ALVARENGA
  • FRANCISCO RICARDO CUNHA

Abstract

IN THIS ARTICLE WE DESCRIBE A BOUNDARY INTEGRAL METHOD FOR CALCULATING THE INCOMPRESSIBLE POTENTIAL FLOW AROUND ARBITRARY, LIFTING, THREE-DIMENSIONAL BODIES. BY USING GREEN THEOREMS TO THE INNER AND OUTER REGIONS OF THE BODY AND COMBINING THE RESULTING EXPRESSIONS WE OBTAIN A GENERAL INTEGRAL REPRESENTATION OF THE FLOW. THE BODY SURFACE IS DIVIDED INTO SMALL QUADRI LATERAL AND TRIANGULAR ELEMENTS AND EACH ELEMENT HAS A CONSTANT SINGULARITIES DISTRIBUTION OF SINKS AND DIPOLES. AN INTERNAL CONSTRAINT IS USED AND THE SINK DISTRIBUTION IS ETERMINED BY AN EXTERNAL NEUMANN BOUNDARY CONDITION. THE APPLICATION OF KUTTA'S CONDITION IS QUITE SIMPLE; NO EXTRA EQUATION OR TRAILING-EDGE VELOCITY POINT EXTRAPOLATION ARE REQUIRED. THE METHOD IS ROBUST WITH A LOW COMPUTATIONAL COST EVEN WHEN IT IS EXTENDED TO SOLVE COMPLEX THREE-DIMENSIONAL BODY GEOMETRIES. CALCULATIONS OF THE PRESSURE COE±CIENT, LIFT COEFFCIENT AND INDUCED DRAG COEFFCIENT ARE COMPUTED BY THE BOUNDARY INTEGRAL NUMERICAL SIMULATIONS. THE BOUNDARY INTEGRAL CODE DEVELOPED HERE IS VERIFIED BY COMPARING THE NUMERICAL PREDICTIONS WITH EXPERIMENTAL MEASUREMENTS, ANALYTICAL SOLUTIONS AND RESULTS OF THE LIFTING-LINE THEORY AND VORTEX-LATTICE METHOD.

Published

2006-06-01

Issue

Section

Articles