Hema Murty

Shanti Engineering and Research · Research and Analysis

This report addresses development of a rotor state/trim modeling capability for noise modeling of decelerating rotorcraft approaches. The resulting technique employs discretization of the descent trajectory as multiple steady state segments for input to CAMRAD.Mod 1 to predict rotor states for acoustic analysis. Deceleration is included by modifyin...

Active control of transonic flutter is investigated for airfoils using a control momentum gyro (CMG). An unsteady, two-dimensional full potential code was used to compute the aerodynamic loads and moments. The equation of motion for the CMG was included as part of the coupled system of equations. A U-g flutter analysis was carried out for various v...

An investigation of wave propagation in transonic flows is carried out using the nonlinear transonic small disturbance equation. The wave fronts are computed from numerical integration of the characteristic equation. The manner in which downstream disturbances, initiated at an airfoil trailing egde, travel to the shock wave is analyzed. Through a r...

The purpose of this work is to study the effects of nonlinear transonic flow on the flutter characteristics of an airfoil. An unsteady, full potential code was developed for this analysis. Linear flutter analysis and nonlinear time response analysis gave different results in some cases. To date, there has been no systematic study of the effects of...

This note reports on results about the occurence of nonunique solutions in unsteady transonic flows. A full potential unsteady code was developed and used. This code was applied to the analysis of flow past airfoils.

A survey of the progress made in the development of numerical simulation techniques for unsteady transonic flow calculations is presented. Computational methods in three-dimensional unsteady transonic flows concentrate mainly on the transonic small disturbance equation and time-lineraization approach. An algorithm is introduced for solving flutter...

The flow in a non-uniform shock tube with driver and channel sections of different cross-sectional areas, separated by a convergent-divergent throat section in which the diaphragm is located, is studied both analytically and numerically. A one-dimensional, quasi-steady flow analysis is applied, by using both isentropic-flow equations and non-isentr...