Date of Award

5-2019

Document Type

Thesis - Open Access

Degree Name

Master of Science in Aerospace Engineering

Department

Graduate Studies

Committee Chair

Dr. Mark Ricklick

First Committee Member

Dr. J. Gordon Leishman

Second Committee Member

Dr. Ebenezer Gnanamanickam

Abstract

The present thesis proposes a preliminary analysis to predict the aerodynamic performance for experimental tests of ram-air parachutes in a wind tunnel. A scaled experimental test setup is developed for determining the aerodynamic coefficients of lift (𝐢𝐿) and drag (𝐢𝐷) conducted in a wind tunnel. Additionally, a CFD approach where a steady-state parachute shape defined based on experiments, photographs, and literature, is presented. The accuracy of the simulation depends considerably on the ability to resolve the canopy geometry. Therefore, a CAD geometry generation is implemented for flexible control of the canopy structure by implementing design parameters, e.g., chord, span and planform shape. Distortions caused by inflation and suspension line tensions on the canopy structure are simulated by the manipulation of the surfaces in the CAD design. The numerical results compared with experimental data from the literature under similar flow conditions showed good agreement for the values of 𝐢𝐿 and a relative constant offset for the values of 𝐢𝐷 for the range of angles of attack analyzed. The difference for the values of 𝐢𝐷 was attributed mainly to effects of the geometry deformation and suspension lines drag during the experimental tests. Additionally, simulations with a domain size equal to the dimensions of a wind tunnel test section showed an increase of 26% in the lift curve slope and strong wing tip vortices compared to the baseline model because of wall interaction effects. Finally, experimental tests using correction factors to compensate lift and drag measurements are recommended to directly validate the numerical results.

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