22 research outputs found
Spatial linear global instability analysis of the HIFiRE-5 elliptic cone model flow
The linear instability of the three-dimensional boundary-layer over the HIFiRE-5 flight test geometry, i.e. a rounded-tip 2:1 elliptic cone, at Mach 7, has been analyzed through spatial BiGlobal analysis, in a effort to understand transition and accurately predict local
heat loads on next-generation ight vehicles. The results at an intermediate axial section of the cone, Re x = 8x10 5, show three different families of spatially amplied linear global modes, the attachment-line and cross- ow modes known from earlier analyses, and a new global mode, peaking in the vicinity of the minor axis of the cone, termed \center-line mode". We discover that a sequence of symmetric and anti-symmetric centerline modes exist and, for the basic ow at hand, are maximally amplied around F* = 130kHz. The wavenumbers and spatial distribution of amplitude functions of the centerline modes are documente
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Crop response to warming soils above their natural temperatures
Multiple use of waste heat from power plants may become an important consideration in their development and siting. The heat in the cooling water must be considered a resource to be managed for effective use. Soil warming was suggested as one of several possible productive uses for the heated discharges. The subsurface application of heat to soil by circulating the warm water through a network of buried pipes was proposed. In geographical regions where soil temperature limits plant growth such a system might be ope rated profitably. It was further suggested that the piping system also might be used to supply water to an overhead irrigation system or as a subsurface irrigation system with thermal gradients enhancing water distribution.Published January 1974. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo
Experimental Test Case
Over the last several years, there has been increasing demand from ablation scientists to have open access to an ablative material. On the modeling side, researchers want to verify and test the various models used in their codes. Similarly, experimentalists want to benchmark their measurement techniques and study specific aspects of the ”real” materials. Unfortunately, most materials used for current re-entry applications fall under ITAR regulations, and are therefore unavailable to international researchers. This has the effect of inhibiting collaboration with academia, even within US institutions. Moreover, even within the confines of the ITAR regulations, data exchange is tedious and time consuming.
It is the hope of this panel to explore and propose solutions to this problem. One possible solution is to study a non-flyable, non-ITAR restricted material that is currently used for commercial applications. That material, if judged suitable for such a task, could be used as a basis for experimental and theoretical ablation studies. Other solutions, such as designing a light weight, non-flyable ablator similar to ablators in current use, will also be explored. Finally, the feasibility of re-regulating restricted materials will also be discussed.
In the event of a material being selected, it is also the hope of this panel to start devising an experimental inter-comparison exercise, which will provide results to calibrate and verify material response codes