Scientific and Technical Aerospace Reports PDF Download

Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 296

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Author: Howard S. Carter
Publisher:
ISBN:
Category : Aerodynamic heating
Languages : en
Pages : 38

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Heat-transfer rates have been measured in free flight along the stagnation line of an unswept cylinder mounted transversely on an axial cylinder so that the shock wave from the hemispherical nose of the axial cylinder intersected the bow shock of the unswept transverse cylinder. Data were obtained at Mach numbers from 2.53 to 5.50 and at Reynolds numbers based on the transverse cylinder diameter from 1.00 x 106 to 1.87 x 106. Shadowgraph pictures made in a wind tunnel showed that the flow field was influenced by boundary-layer separation on the axial cylinder and by end effects on the transverse cylinder as well as by the intersecting shocks. Under these conditions, the measured heat-transfer rates had inconsistent variations both in magnitude and distribution which precluded separating the effects of these disturbances. The general magnitude of the measured heating rates at Mach numbers up to 3 was from 0.1 to 0.5 of the theoretical laminar heating rates along the stagnation line for an infinite unswept cylinder in undisturbed flow. At Mach numbers above 4 the measured heating rates were from 1.5 to 2 times the theoretical rates.

Author: Oleg Roussak
Publisher: Springer Science & Business Media
ISBN: 1461442613
Category : Science
Languages : en
Pages : 383

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This updated edition of Gesser’s classic textbook has undergone a full revision and now has the latest material, including new chapters on semiconductors and nanotechnology. It includes a supplementary laboratory section with stepwise experimental protocols.

Author: Lev Solomonovich Polak
Publisher: Cambridge International Science Publishing
ISBN:
Category : Science
Languages : en
Pages : 416

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The book describes the results of investigations of the electrophysical, chemical, gas-dynamic and other processes in low-temperature plasma, their diagnostics, modelling and application in various areas of science and technology. Special attention is given to the problems associated with physico-chemical processes and chemical reactions in nonequilibrium and (quasi) equilibrium low-temperature plasma. Kinetic and thermodynamic aspects of plasmochemical reactions and their mechanisms, determined mainly by reactions under electron impacts and reactions of vibrationally excited molecules, are discussed.

Author:
Publisher:
ISBN:
Category : Trailers
Languages : en
Pages : 186

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Author: David Ferry
Publisher: Springer Science & Business Media
ISBN: 9780306438813
Category : Science
Languages : en
Pages : 616

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The technological means now exists for approaching the fundamentallimiting scales of solid state electronics in which a single carrier can, in principle, represent a single bit in an information flow. In this light, the prospect of chemically, or biologically, engineered molccular-scale structures which might support information processing functions has enticed workers for many years. The one common factor in all suggested molecular switches, ranging from the experimentally feasible proton-tunneling structure, to natural systems such as the micro-tubule, is that each proposed structure deals with individual information carrying entities. Whereas this future molecular electronics faces enormous technical challenges, the same Iimit is already appearing in existing semiconducting quantum wires and small tunneling structures, both superconducting and normal meta! devices, in which the motion of a single eh arge through the tunneling barrier can produce a sufficient voltage change to cut-off further tunneling current. We may compare the above situation with today's Si microelectronics, where each bit is encoded as a very !arge number, not necessarily fixed, of electrons within acharge pulse. The associated reservoirs and sinks of charge carriers may be profitably tapped and manipulated to proviele macro-currents which can be readily amplified or curtailed. On the other band, modern semiconductor ULSI has progressed by adopting a linear scaling principle to the down-sizing of individual semiconductor devices.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309184924
Category : Technology & Engineering
Languages : en
Pages : 148

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After the completion of the National Research Council (NRC) report, Maintaining U.S. Leadership in Aeronautics: Scenario-Based Strategic Planning for NASA's Aeronautics Enterprise (1997), the National Aeronautics and Space Administration (NASA) Office of Aeronautics and Space Transportation Technology requested that the NRC remain involved in its strategic planning process by conducting a study to identify a short list of revolutionary or breakthrough technologies that could be critical to the 20 to 25 year future of aeronautics and space transportation. These technologies were to address the areas of need and opportunity identified in the above mentioned NRC report, which have been characterized by NASA's 10 goals (see Box ES-1) in "Aeronautics & Space Transportation Technology: Three Pillars for Success" (NASA, 1997). The present study would also examine the 10 goals to determine if they are likely to be achievable, either through evolutionary steps in technology or through the identification and application of breakthrough ideas, concepts, and technologies.

Author: Charles B. Rumsey
Publisher:
ISBN:
Category : Aerodynamic heating
Languages : en
Pages : 26

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Aerodynamic-heat-transfer measurements have been made at a station on the 10 degree total angle conical nose of a rocket-propelled model at flight Mach numbers of 1.4 to 3.9. The corresponding values of local Reynolds number varied from 18,000,000 to 46,000,000 and the ratio of skin temperature to local static temperature varied from 1.2 to 2.4. The experimental data, reduced to Stanton number, were in fair agreement with values predicted by Van Driest's theory for heat transfer on a cone with turbulent flow from the nose tip.

Author: K. R. Czarnecki
Publisher:
ISBN:
Category : Body of revolution
Languages : en
Pages : 23

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A preliminary investigation has been made of the effects of heat transfer on boundary-layer transition on a body of revolution at a Mach number of 1.61 and over a Reynolds number range of 7,000,000 to 20,000,000, based on body length. The body had a parabolic-arc profile, blunt-base, and a fineness ratio of 12.2 (NACA RM-10). The results indicated that, by cooling the model an average of about 50 degrees F, the Reynolds number for which laminar boundary-layer flow could be maintained over the entire length of the body was increased from the value of 11,500,000 without cooling to over 20,000,000, the limit of the present tests. Heatig the model an average of about 12 degrees F on the other hand decreased the transition Reynolds number from 11,500,000 to about 8,000,000. These effects of heat transfer on transition were considerably larger than previously found in similar investigations in other wind tunnels. It appears that, if the boundary-layer transition Reynolds number for zero heat transfer is large, as in the present experiments, then the sensitivity of transition to heating or cooling is high; if the zero-heat-transfer transition Reynolds number is low, then transition is relatively insensitive to heat-transfer effects.

Author: Morton Cooper
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 42

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