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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Hypersonic test facilities: requirements analysis and preliminary design

Drauch, Gregory Andrew 07 April 2009 (has links)
There has come about, in recent years, a renewed interest in aerospace vehicles operating in the hypersonic regime. With this interest has come a need to not only reestablish the hypersonic test capability that was available in the 1960s but to enhance this capability to meet the demanding needs of today's proposed vehicles. This will require more capable hypersonic wind tunnels with larger test sections, longer run times, and test gases more closely resembling the fluid to be encountered by the vehicle being developed. This document will review the current hypersonic testing capability, examine the operating characteristics of several hypersonic vehicles to develop a set of hypersonic testing requirements, and develop a preliminary design of a required hypersonic facility that addresses the demonstrated requirements. An order of magnitude cost estimate is also presented. / Master of Science
2

Efficient inverse methods for supersonic and hypersonic body design, with low wave drag analysis

Lee, Jaewoo 26 February 2007 (has links)
With the renewed interest in the supersonic and hypersonic flight vehicles, new inverse Euler methods are developed in these flow regimes where a space marching numerical technique is valid. In order to get a general understanding for the specification of target pressure distributions, a study of minimum drag body shapes was conducted over a Mach number range from 3 to 12. Numerical results show that the power law bodies result in low drag shapes, where the n=.69 (l/d = 3) or n=.70 (l/d = 5) shapes have lower drag than the previous theoretical results (n=.75 or n=.66 depending on the particular form of the theory). To validate the results, a numerical analysis was made including viscous effects and the effect of gas model. From a detailed numerical examination for the nose regions of the minimum drag bodies, aerodynamic bluntness and sharpness are newly defined. Numerous surface pressure-body geometry rules are examined to obtain an inverse procedure which is robust, yet demonstrates fast convergence. Each rule is analyzed and examined numerically within the inverse calculation routine for supersonic (M<sub>∞ </sub>= 3) and hypersonic (M<sub>∞ </sub> = 6.28) speeds. Based on this analysis, an inverse method for fully three dimensional supersonic and hypersonic bodies is developed using the Euler equations. The method is designed to be easily incorporated into existing analysis codes, and provides the aerodynamic designer with a powerful tool for design of aerodynamic shapes of arbitrary cross section. These shapes can correspond to either "wing like" pressure distributions or to "body like" pressure distributions. Examples are presented illustrating the method for a non-axisymmetric fuselage type pressure distribution and a cambered wing type application. The method performs equally well for both nonlifting and lifting cases. For the three dimensional inverse procedure, the inverse solution existence and uniqueness problem are discussed. Sample calculations demonstrating this problem are also presented. / Ph. D.

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