Flutter Analysis of MBB A-3 Supercritical Airfoil in Small Disturbance Transonic Flow

1981 ◽  
Vol 18 (10) ◽  
pp. 887-890
Author(s):  
T. Y. Yang ◽  
A. G. Striz ◽  
P. Guruswamy
Keyword(s):  
Transonic Flow ◽  
Small Disturbance ◽  
Supercritical Airfoil ◽  
Flutter Analysis

Flutter analysis of a NACA 64A006 airfoil in small disturbance transonic flow

1980 ◽  
Vol 17 (4) ◽  
pp. 225-232 ◽  
Author(s):  
T. Y. Yang ◽  
P. Guruswamy ◽  
Alfred G. Striz ◽  
James J. Olsen
Keyword(s):  
Transonic Flow ◽  
Small Disturbance ◽  
Flutter Analysis

Transonic flow of moist air around a thin airfoil with non-equilibrium and homogeneous condensation

2000 ◽  
Vol 403 ◽  
pp. 173-199 ◽  
Author(s):  
ZVI RUSAK ◽  
JANG-CHANG LEE
Keyword(s):  
Transonic Flow ◽  
Droplet Growth ◽  
Inviscid Fluid ◽  
Small Disturbance ◽  
Moist Air ◽  
Integration Rule ◽  
Flow Equations ◽  
Homogeneous Condensation ◽  
Thin Airfoil ◽  
Non Equilibrium

A new small-disturbance model for a steady transonic flow of moist air with non-equilibrium and homogeneous condensation around a thin airfoil is presented. The model explores the nonlinear interactions among the near-sonic speed of the flow, the small thickness ratio and angle of attack of the airfoil, and the small amount of water vapour in the air. The condensation rate is calculated according to classical nucleation and droplet growth models. The asymptotic analysis gives the similarity parameters that govern the flow problem. Also, the flow field can be described by a non-homogeneous (extended) transonic small-disturbance (TSD) equation coupled with a set of four ordinary differential equations for the calculation of the condensate (or sublimate) mass fraction. An iterative numerical scheme which combines Murman & Cole's (1971) method for the solution of the TSD equation with Simpson's integration rule for the estimation of the condensate mass production is developed. The results show good agreement with available numerical simulations using the inviscid fluid flow equations. The model is used to study the effects of humidity and of energy supply from condensation on the aerodynamic performance of airfoils.

Transonic equivalence rule: a nonlinear problem involving lift

1975 ◽  
Vol 72 (1) ◽  
pp. 161-187 ◽  
Author(s):  
H. K. Cheng ◽  
M. M. Hafez
Keyword(s):  
Transonic Flow ◽  
Line Source ◽  
Sectional Area ◽  
Small Disturbance ◽  
Cross Sectional ◽  
Outer Flow ◽  
Nonlinear Structure ◽  
First Order ◽  
Lift Control ◽  
Area Rule

The inviscid transonic flow past a thin wing having swept leading edges, with smooth lift and thickness distributions, is shown to possess an outer nonlinear structure determined principally by a line source and a line doublet. Three domains (the thickness-dominated, the intermediate, and the lift-dominated), representing different degrees of lift control of the outer flow, are identified; a transonic equivalence rule valid in all three domains is established. Except in one domain, departure from the Whitcomb-Oswatitsch area rule is significant; the equivalent body corresponding to the source effect has an increased cross-sectional area depending nonlinearly on the lift. This nonlinear lift contribution results from the second-order corrections to the inner (Jones) solution, but produces effects of first-order importance in the outer flow. Of interest is an afterbody effect dependent on the vortex drag, which is not accounted for by the classical transonic small-disturbance theory.

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