Experimental Studies on a 1/12 Scale Model of Prithvi Missile

Wind Tunnel Tests were carried out to determine the Longitudinal. static stability and roll control characteristics of a 1/12 scale 'PRITHVI' missile configuration with cruciform trapezoidal wings and aft tail fin controls . The tests were conducted ih the 1 .2m Trisonic wind tunnel at Mach numbers from 0 .4 to 1 .5 through an angle of attack range of -10° to 20° . Model roll orientation was varied from -45° to 45 ° . The results indicated good longitudinal stability characteristics throughout the test Mach number range

Wind Tunnel Force Measurements on 1/12 Scale Model of PRITHVI missile Configuration - II : Final Report

This report presents the aerodynamic data generated on a 1/12 scale model of PRITHVI missile configuration - II through tests in the NAL 1.2m wind tunnel. The tests were carried out to obtain aerodynamic data to determine the control effectiveness characteristics of the tail fin Controlled missile model. The presentation of test results include the following : (i) basic tests (without CDS) and roll effectiveness tests at M=0.4 to 1.2 (ii) Pitch and yaw effectiveness tests in the Mach number range 1.5 to 3.5 (iii) Effect of protrusions on the basic configuration. The test Reynolds number based on the body diameter varied from 1.1 million to 2.8 million. Complete test results are given in the form of tables with few typical plots

Experimental Investigation on Plain Circular and 2:1 Rectangular Jets at Low Speed

= jet half-width growth along major-axis plane, mm δ mi = jet exit shear-layer thickness along minor-axis plane, mm δ mj = jet exit shear-layer thickness along major-axis plane, m

Some studies on induced rolling moment of a missile type configuration 13; 13;

Force tests were carried out on a typical missile configuration, featuring a slender body cruciform canard and cruciform tail, in a 1.2-m wind tunnel at subsonic, transonic, and supersonic speeds at various incidence and control deflections. Some discussions on the induced rolling moment experienced by this configuration during maneuvering attitudes are presented. It was observed that the induced rolling moment was primarily due to the interaction of asymmetric flow field induced by the canard deflections on the tail. This induced rolling moment was negligibly small when the tail fins were removed. Also, the variation of the induced rolling moment with incidence was approximately sinusoidal for most of the canard deflections. This paper also includes some discussions on a current method adopted for eliminating such undesirable induced rolling moments by allowing the tail fin to roll freely

Estimation of error in measurement of force and moment coefficients of wind tunnel models

It 1s general practice to give the accuracy of measurement of moment and force coefficients from wind tunnel, repeatability tests and the level of uncertainties estimated from various instruments used. However, since the repeatability tests could't be carried out, a method based on the principle of propagation of errors has been used to get the accuracy in force and moment coefficients derived from errors in measurements of all independent parameters. A computer code has been written to get the level of uncertainties and percentage of ,error of various coefficients measured. ,The.listing of the code is given along with the sample output in th form of tables and graphs

Aerodynamic characteristics of pretensioned elastic membrane rectangular sailwings

Presented in the paper are the details of a method for obtaining aerodynamic characteristics of pretensioned elastic membrane rectangular sailwings. This is a nonlinear problem governed by the membrane equation for the inflated sail and the lifting surface theory integral equation for aerodynamic loads on the sail. Assuming an admissible mode shape for the inflated elastic sail, an iterative procedure based on a doublet lattice method is employed to determine the inflated configuration as well as various aerodynamic characteristics. Application of the method is made to a typical nylon-cotton sailwing of AR = 6.0 and results are presented graphically to show the effect of various parameters. The results are found to tend to plane wing values when the pretensions are large in magnitude