
Accession Number : ADA302254
Title : Comparison of Two ShockCapturing Methods for Calculation of Transonic Airfoil Flutter.
Descriptive Note : Master's thesis,
Corporate Author : AIR FORCE INST OF TECH WRIGHTPATTERSON AFB OH
Personal Author(s) : Buxton, Bradley J.
PDF Url : ADA302254
Report Date : DEC 1995
Pagination or Media Count : 108
Abstract : The flutter of a pitchandplunge airfoil (PAPA) in transonic flow is simulated using two shockcapturing methods. Each method solves a coupled system of equations involving the unsteady Euler equations and a twodegreeoffreedom structural model. The first method, TVDntiAE, uses an explicit TotalVariationDiminishing (TVD) algorithm to compute the flowfield for a 2D airfoil. The second method, ENS3DAE, uses an implicit BeamWarming approach to compute the flowfleld on a 3D rectangular wing while enforcing 2D flow. Results of the schemes are compared with each other and against limited published data to extend the validation of the software to unsteady fluid/structure interactions. Results are compared for three airfoil configurations: (1) static; (2) forced oscillation; and (3) PAPA. Computation of flutter points is of special interest. ENS3DAE predicts a flutter onset speed for the NACA 64A006 airfoil at M=0.87 that is 1% greater than the value predicted by TVDntiAE and 2% smaller than the published data. Variations in model predictions most likely due to dissipationmodel differences and grid and timestep sensitivities are evaluated. (AN)
Descriptors : *FLUTTER, *TRANSONIC FLOW, *TRANSONIC AIRFOILS, MATHEMATICAL MODELS, ALGORITHMS, STEADY STATE, PITCH(MOTION), TIME DEPENDENCE, VALIDATION, AERODYNAMIC STABILITY, STRUCTURAL ANALYSIS, COMPARISON, SHOCK WAVES, AIR FLOW, ACCURACY, THESES, COMPUTATIONAL FLUID DYNAMICS, ANGLE OF ATTACK, DEGREES OF FREEDOM, AEROELASTICITY, FLOW FIELDS, AERODYNAMIC LOADING, MACH NUMBER, TWO DIMENSIONAL FLOW, UNSTEADY FLOW, INVISCID FLOW, INSTABILITY, PRESSURE DISTRIBUTION, AERODYNAMIC LIFT, GAS SURFACE INTERACTIONS, RUNGE KUTTA METHOD, WING TIPS, TRANSONIC CHARACTERISTICS.
Subject Categories : Aerodynamics
Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE