Download or read book Optimum Shape for Transpiration cooled Nosetip of a Re entry Vehicle written by Kevin E. Yelmgren and published by . This book was released on 1978 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The variations of parameters method was used to determine the optimum nose shape for a reentry vehicle having a transpiration-cooled nosetip (TCNT). Three families of nose shapes were considered - The oblate ellipsoid, the flat face - round shoulder, and the spherical arc - round shoulder. These families are bounded by the flat face - sharp corner at one extreme and the hemisphere at the other extreme. The amount of coolant required by each nose shape during reentry was determined by using a high speed computer to couple the aerodynamic equations with the trajectory equations. The optimum shape is the shape which requires the least amount of coolant for reentry. The flat face - sharp corner shape was found to require the least amount of coolant, about 60 percent less water than the hemisphere. Although the time to impact is longer for the flat face, the smaller surface area and lower heating intensity more than offsets the increased reentry time. The possibility of an optimum flat face height was also investigated; no face height was found that minimized the total heating to the vehicle during reentry. (Author).
Download or read book Development of an Analytic Model of the Response of Self contained Transpiration cooled Nose Tips to Reentry Environments written by I. M. Grinberg and published by . This book was released on 1968 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Discussion and Analysis of Some Aspects of Transpiration Cooled Nosetips written by R. A. Gater and published by . This book was released on 1969 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transpiration cooling of a porous nosetip of a hypersonic reentry vehicle employing water as a coolant is considered. Fundamental problem areas are discussed, and those requiring considerably more analytical and/or experimental investigation are noted. Analysis and example calculations are presented for the local rate of mass transfer from the liquid surface film to the proximate gas stream. Particular emphasis is placed upon evaluating the relative importance of the mass transfer contributions due to evaporation from an idealized smooth film surface, additional evaporation due to the 'effective' roughness of the film surface; and entrainment of bulk liquid from the film surface due to shear interaction with the gas flow. Correspondingly, computed results for downstream cooling effectiveness are presented for hypersonic reentry type flow conditions. In addition, analyses are developed and example calculations are presented for film surface temperature, mean film thickness, and mean film surface velocity. Finally, some specific recommendations are made for future research effort. (Author).
Download or read book Test Plan Optimization for Reentry Vehicle Nose Tip Evaluation written by Roald A. Rindal and published by . This book was released on 1967 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nose Tip Shape Optimization for Minimum Transpiration Coolant Requirements written by R. L. Baker and published by . This book was released on 1980 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expressions for the total heat transfer to a nose tip for a realistic reentry trajectory have been obtained by using local laminar and turbulent convective heat transfer relationships and extending the trajectory integration procedures of earlier investigators. Then, employing approximate relationships for the boundary layer edge properties along the nose tip surface, a variational calculus approach to determine nose tip shapes which minimize the total trajectory heat transfer (coolant requirements) for fixed fineness ratio and reentry parameters is utilized. The calculated minimum heat transfer shapes found have a flat nose with an expansion corner followed by an afterbody with monotonically decreasing slope. The height of the flat nose relative to the base radius decreases as the fineness ratio decreases. However, for fineness ratios greater than 0.2, the laminar and turbulent solution shapes were found to be very similar to one another. For fineness ratios approaching zero (i.e., slender bodies), the laminar and turbulent minimum heat transfer shapes are 1/2 and 8/13 power law bodies, respectively. The relative heat transfer rate to a particular one of the minimum heat transfer shapes was found to be a factor of up to three times lower than that for other body shapes having the same fineness ratio.
Download or read book Technical Abstract Bulletin written by and published by . This book was released on 1978 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transpiration Cooling System Development for Reentry Vehicles written by and published by . This book was released on 1968 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reentry Vehicle Nosetip Design for Minimum Total Heat Transfer written by and published by . This book was released on 1982 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: A direct optimization method has been used to determine fixed fineness ratio nosetip shape contours for a specified vehicle ballistic coefficient; and nosetip scale, which minimize the total trajectory nosetip laminar or turbulent heat transfer. These constraints neglect the interaction of the nosetip shape with vehicle performance characteristics. When this interaction is taken into account and additional new constraints of constant mass and volume are applied, truncated cone nosetips are shown to result in the lowest total nosetip heat transfer. No attempt was made to optimize nosetip shape for the latter constraints.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1980 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Investigation of Boundary Layer Relaminarization on a Reentry Vehicle Nosetip written by Calvin J. Wolf and published by . This book was released on 1975 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: A correlation for the distribution of heat transfer on a nosetip with a relaminarized boundary layer is developed and implemented in a general nosetip shape change code. A sensitivity study is made that shows that relaminarization results in significantly reduced heating rates in the sphere-cone tangent region of a reentry nosetip. This locally reduced heating is expected to have an impact, not as yet quantified, on the thermostructural performance of the nosetip.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1979-11 with total page 1064 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Collection of Technical Papers written by and published by . This book was released on 1977 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Newsletter written by Cornell University. Engineering Library and published by . This book was released on 1979 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1979 with total page 1324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1979 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Download or read book AIAA Bulletin written by and published by . This book was released on 1973 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1996 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:
