Under NASA Glenn Research Center sponsorship, MIT has developed the concept of micromachined, bipropellant, liquid rocket engines. This is potentially a breakthrough technology changing the cost-performance tradeoffs for small propulsion systems, enabling new applications, and redefining the meaning of the term low-cost-access-to-space. With this NASA support, a liquid-cooled, gaseous propellant version of the thrust chamber and nozzle was designed, built, and tested as a first step. DARPA is...

Topics: NASA Technical Reports Server (NTRS), LIQUID PROPELLANT ROCKET ENGINES, MICROMACHINING, MICROROCKET...

The fluid mechanics of multi-phase flow breakup of liquid nitrogen, LN2, jets injected into sonic velocity nitrogen gasflow, was experimentally investigated. A scattered-light scanning instrument was used to measure the characteristic dropsize, D(sub v.5), of LN2 sprays and to determine the effect of droplet vaporization on experimental dropsize measurements. Under sonic gas-velocity conditions, liquid-jet breakup occurred in the regime of aerodynamic stripping. As a result, the following...

Topics: NASA Technical Reports Server (NTRS), CRYOGENIC FLUIDS, DROP SIZE, FUEL SPRAYS, GAS JETS, LIQUID...

The Constrained Vapor Bubble (CVB) is a wickless, grooved heat pipe and we report on a full- scale fluids experiment flown on the International Space Station (ISS). The CVB system consists of a relatively simple setup a quartz cuvette with sharp corners partially filled with either pentane or an ideal mixture of pentane and isohexane as the working fluids. Along with temperature and pressure measurements, the two-dimensional thickness profile of the menisci formed at the corners of the quartz...

Topics: NASA Technical Reports Server (NTRS), BUBBLES, INTERNATIONAL SPACE STATION, VAPORS, MARANGONI...

It has been shown that the phenomenon of reciprocity which is known in physics also occurs in the case on non-established heat propagation in a solid, specifically if the heat sources is located at point 1 and at point 2 causes a temperature change delta t, then when the sources is shifted to point 2 at point 1 there occurs the same change in temperature delta t. This makes it possible to obtain analytical solutions to some already known problems, as well as the new problems. The application of...

Topics: DTIC Archive, Pekhovich,A I, COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H, *HEAT TRANSFER,...

This thesis determines the magnitude of heat transfer in the high-pressure compressor of a turbofan engine during a 'Bodie' throttle transient and estimates the effect of transient heat transfer on compressor blade boundary layer growth. Total stored thermal energy available for release is determined considering compressor blades and roots only. Thermal energy released during a throttle transient is determined and allocated to individual compressor stages and used to estimate blade heat flux....

Topics: DTIC Archive, Wood,C W, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH, *HEAT TRANSFER, *BOUNDARY...

The influence of the large variation of thermodynamics and transport properties near the pseudocritical temperature on the heat transfer coefficient of supercritical fluid in turbulent flow was studied. The formation of the characteristics peak in the heat transfer coefficient vs. bulk temperature curve is described, and the necessity of the fluid element at pseudocritical temperature located in the buffer layer is discussed.

Topics: NASA Technical Reports Server (NTRS), HEAT TRANSFER COEFFICIENTS, SUPERCRITICAL FLOW, THERMODYNAMIC...

This report discusses in detail the input parameters used in computing flame speeds and profiles for the stoichiometric hydrogen-air premixed, steady-state, laminar flame. The input kinetics were specified. OUr solution was obtained by use of a relaxation technique. The partial differential equations were solved using a finite element method, PDECOL. A special algorithm that enabled spatial grid points to be placed in the flame front was used. Results include: (1)information requested by the...

Topics: DTIC Archive, Heimerl,Joseph M, ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD,...

Shock tube experiments were performed in order to determine the response of a single hot-film element of a sensor array to transiently induced flow behind weak normal shock waves. The experiments attempt to isolate the response due only to the change in convective heat transfer at the hot-film surface mounted on the wall of the shock tube. The experiments are described, the results being correlated with transient boundary layer theory and compared with an independent set of experimental...

Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER SEPARATION, BOUNDARY LAYERS, CONVECTIVE HEAT...

A mathematical model was developed to describe the heat transfer characteristics of a hot strand emerging into a surrounding coolant. A stable strand of constant efflux velocity is analyzed, with a constant (average) heat transfer coefficient on the sides and leading surface of the strand. After developing a suitable governing equation to provide an adequate description of the physical system, the dimensionless governing equation is solved with Laplace transform methods. The solution yields the...

Topics: NASA Technical Reports Server (NTRS), EXTRUDING, HEAT TRANSFER, EFFLUX, HEAT TRANSFER COEFFICIENTS,...

A procedure for computing the rotor temperature and stress distributions in a cooled radial turbine are considered. Existing codes for modeling the external mainstream flow and the internal cooling flow are used to compute boundary conditions for the heat transfer and stress analysis. The inviscid, quasi three dimensional code computes the external free stream velocity. The external velocity is then used in a boundary layer analysis to compute the external heat transfer coefficients. Coolant...

Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYERS, COOLANTS, FLOW VELOCITY, GAS TURBINE...

Results are presented for a preliminary experiment involving saturated pool boiling at 1 atm from rotating 2 and 3 in. diameter spheres which were immersed in liquid nitrogen (LN2). Additional results are presented for a stationary, 2 inch diameter sphere, quenched in LN2, which were obtained utilizing a more versatile and complete experimental apparatus that will eventually be used for additional rotating sphere experiments. The speed for the rotational tests was varied from 0 to 10,000 rpm....

Topics: NASA Technical Reports Server (NTRS), BALL BEARINGS, FILM BOILING, HEAT TRANSFER COEFFICIENTS,...

A technique is developed to measure the local convective heat transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local heat flux at the model test surface, and an infrared camera system determines the local temperature distribution due to heating. From this temperature distribution and an analysis of the heating process, a local convective heat transfer coefficient is determined. The technique was used to measure the load surface...

Topics: NASA Technical Reports Server (NTRS), CONVECTIVE HEAT TRANSFER, FLAT PLATES, FLOW DISTRIBUTION,...

Experimental and computational studies have been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (greater than 100 MW) In a previous work the numerical heat transfer results for a sharp edge blade tip and a radiused blade tip were presented. More recently several other tip treatments have been considered for which the tip heat transfer has been measured and...

Topics: NASA Technical Reports Server (NTRS), EXPERIMENTATION, MATHEMATICAL MODELS, CONVECTIVE HEAT...

In spur gears both performance and failure predictions are known to be strongly dependent on the variation of load, lubricant film thickness, and total flash or contact temperature of the contacting point as it moves along the contact path. The need of an accurate tool for predicting these variables has prompted the development of a computer code based on recent findings in EHL and on finite element methods. The analyses and some typical results which to illustrate effects of gear geometry,...

Topics: NASA Technical Reports Server (NTRS), DYNAMIC LOADS, FILM THICKNESS, GEARS, LUBRICATION, SURFACE...

The 2109-kW (2828-hp) UH-60A Black Hawk helicopter transmission was one of the transmissions used to obtain an experimental data base. Component improvements or new transmission concepts can thus be evaluated by comparison with the established data. Results of efficiency and vibration tests of the UH-60A have been reported previously. In this investigation the transmission was instrumented internally and tested over a range of operating conditions. The speed was varied from 50 to 100 percent of...

Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, HELICOPTER PROPELLER DRIVE,...

Shock tube experiments were performed to determine the response of a hot-film sensor, mounted flush on the side wall of a shock tube, to unsteady flow behind a normal shock wave. The present experiments attempt to isolate the response of the anemometer due only to the change in convective heat transfer at the hot-film surface. The experiments, performed at low supersonic shock speeds in air, are described along with the data acquisition procedure. The change in convective heat transfer is...

Topics: NASA Technical Reports Server (NTRS), CONVECTIVE HEAT TRANSFER, FLOW MEASUREMENT, HEAT TRANSFER...

The work done during the progress report period from May-October 1992 is summarized. The effect of wall thermal boundary conditions on flows over a step or rib when repeated rib roughness is used for heating augmentation is examined. In numerical investigations of various such laminar and turbulent flows, the local heat transfer coefficients on a forward-facing step or on a rib were found to be very sensitive to the wall thermal boundary condition. For the computation of constant property...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC HEAT TRANSFER, BOUNDARY CONDITIONS, COMPUTATIONAL...

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843

Jul 11, 2010
07/10

by
Jones, R. T

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The problem of the minimum induced drag of wings having a given lift and a given span is extended to include cases in which the bending moment to be supported by the wing is also given. The theory is limited to lifting surfaces traveling at subsonic speeds. It is found that the required shape of the downwash distribution can be obtained in an elementary way which is applicable to a variety of such problems. Expressions for the minimum drag and the corresponding spanwise load distributions are...

Topics: FILM COOLING, HEAT TRANSFER COEFFICIENTS, PLUG NOZZLES, EXHAUST NOZZLES, J-85 ENGINE, SUPERSONIC...

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234

Jun 21, 2010
06/10

by
Libby, J. N.; Schaffert, J. C

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Extra-long monostable multivibrator employing bistable semiconductor switch to allow charging of timing circuit

Topics: HEAT TRANSFER COEFFICIENTS, PLATES (STRUCTURAL MEMBERS), RADIANT HEATING, SURFACE TEMPERATURE,...

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Jun 21, 2010
06/10

by
Kalman, R. E

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No Abstract Available

Topics: APOLLO SPACECRAFT, PRESSURE DISTRIBUTION, COMMAND MODULES, FLOW DISTRIBUTION, HYPERSONIC HEAT...

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238

Jul 11, 2010
07/10

by
DEBIJADJI, R

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PAST EXPERIENCE INDICATES THAT HUMAN STAY IN WEIGHTLESSNESS DURING SPACE FLIGHT INDUCES SOME CHANGES IN THE ASTRONAUT'S BODY FUNCTIONS. THESE CHANGES BECOME ESPECIALLY NOTICEABLE AFTER RETURN TO EARTH GRAVITY CONDITIONS. HOWEVER, THESE CHANGES ARE REVERSIBLE. IN ORDER TO PREVENT THE DECONDITIONING OF THE ORGANISM IN ZERO GRAVITY, CERTAIN COUNTERMEASURES ARE TAKEN. CERTAIN PROTECTIVE TECHNIQUES CAN BE USED TO FACILITATE THE READAPTATION OF THE HUMAN BODY AFTER LANDING ON EARTH.

Topics: CYLINDRICAL BODIES, HEAT TRANSFER, REYNOLDS NUMBER, TURBULENT FLOW, DATA ACQUISITION, FLOW...

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255

May 23, 2011
05/11

by
Zahnle, Kevin; MacLow, Mordecai-Mark; Lodders, Katharina; Fegley, Bruce, Jr

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A curious and unexpected result of the impact of P/Shoemaker Levy 9 with Jupiter was the production of enormous amounts of molecular sulfur (S2). Here we show that S2 is the natural product of disequilibrium chemistry at low pressures in shocked Jovian air, its formation a byproduct of hydrogen recombination. The species observed by the Hubble Space Telescope (HST) - S2, CS2, and H2S - imply that the G fragment penetrated the NH4SH cloud but did not reach the water table. A typical impact...

Topics: CONVECTIVE HEAT TRANSFER, PARALLEL FLOW, HEAT FLUX, HEAT MEASUREMENT, LEADING EDGES, FLOW VELOCITY,...

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228

Jun 21, 2010
06/10

by
Drinkwater, F. J., III; Patton, J. M., Jr.; Price, C

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Research pilots observations of aircraft performance on grooved runway

Topics: ALUMINUM, HEAT TRANSFER COEFFICIENTS, ROCKET NOZZLES, SOLID ROCKET PROPELLANTS, GAS FLOW, METAL...

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185

Jul 9, 2010
07/10

by
PIGGE, H

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OPTIMUM DESIGN METHODS FOR WIND DRIVEN ELECTRICAL GENERATING PLANTS ARE PRESENTED, BASED ON YEARLY PERMANENT WIND LEVEL LINES FOR SELECTED ERECTION SITES. WIND CONDITIONS AT ANY SITE ARE DIVIDED INTO FIVE CLASSES, OF WHICH ONLY A FEW CAN BE EXPLOITED BY A GIVEN SYSTEM. GENERAL PURPOSE DESIGN CURVES ARE GIVEN.

Topics: CALORIMETERS, HEAT TRANSFER, TEMPERATURE CONTROL, FLUID FLOW, HEAT TRANSFER COEFFICIENTS, LIQUID...

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190

Jul 9, 2010
07/10

by
GRIBENSKI, A

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FROM AN EXTENSIVE REVIEW OF THE RECENT LITERATURE, IT IS ATTEMPTED TO CLARIFY THE FOLLOWING RELATIONSHIPS: AFFERENT AND EFFERENT VESTIBULAR INNERVATIONS, AND NERVE CONNECTIONS INVOLVING THE CORTICAL, SUBCORTICAL AND CEREBELLAR ACTIVITIES AND THEIR INFLUENCE ON VESTIBULAR NUCLEI.

Topics: CASING, FLUID FLOW, GAS TURBINE ENGINES, HEAT TRANSFER, LIQUID COOLING, ROTATING DISKS, HEAT...

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331

Sep 20, 2010
09/10

by
Hansen, Vicki L.; Keep, Myra; Herrick, Robert R.; Phillips, Roger J

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Eastern Aphrodite Terra is approximately equal in size to the western North American Cordillera, from Mexico to Alaska. Its size and unique landforms make it an important area for understanding the tectonics of Venus, yet models for its formation are diametrically opposed. This region is part of the Equatorial Highlands, which was proposed as a region of lithospheric thinning, isostatic uplift, and attendant volcanism. Eastern Aphrodite Terra is dominated by circular structures within which...

Topics: CRYOGENIC FLUIDS, DROPS (LIQUIDS), GAS ATOMIZATION, HEAT TRANSFER COEFFICIENTS, DROP SIZE, FUEL...

Topics: DTIC Archive, Francois,J, ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (ENGLAND),...

Ten polymer coatings were evaluated for the long term promotion of dropwise condensation of steam. Four of the coatings were experimental coatings developed by the Naval Research Laboratory and six were commercial coatings. Continuous dropwise condensation in excess of 10,000 hours was obtained for several of the coatings that were applied to rough surfaces. Three commercial coatings, in addition to an NRL fluoroacrylic coating, were evaluated for heat-transfer performance. The effects of...

Topics: DTIC Archive, Looney,D J, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *COATINGS, *STEAM, *CONDENSATION,...

This report describes the results of a brief computational study using the ABRES Shape Change Code, ASCC-79, to predict the effects of aerodynamic heating on an ablating nose cap configuration for the XM797 high velocity training round. Ablation rates and in-depth thermal response are analyzed for three flight trajectories. Recommendations are made for experimental verification of the computational modeling.

Topics: DTIC Archive, Abbett, M J, BATTELLE COLUMBUS DIV OH, *AERODYNAMIC HEATING, *NOSE CAPS, *TRAINING...

A multi-block, three-dimensional Navier-Stokes code has been used to study the within-hole and near-hole physics in relation to heat transfer on a film-cooled blade. The flow domain consists of the coolant flow through the plenum and hole-pipes for the three staggered rows of shower-head holes on the VK1 rotor, and the main flow over the blade. A multi-block grid is generated that is nearly orthogonal to the various surfaces. It may be noted that for the VK1 rotor the shower-head holes are...

Topics: NASA Technical Reports Server (NTRS), FILM COOLING, COOLANTS, HEAT TRANSFER, HEAT TRANSFER...

The primary basis for heat transfer analysis of turbine blades is experimental data obtained in linear cascades. These data have been very valuable in identifying the major heat transfer and fluid flow features of a turbine airfoil. The question of major interest is how well all of these data translate to the rotating turbine blade. It is known from the work of Lokay and Trushin that average heat transfer coefficients on the rotor may be as much as 40 percent above the values measured on the...

Topics: NASA Technical Reports Server (NTRS), FLOW DISTRIBUTION, HEAT TRANSFER, ROTATION, TURBINE BLADES,...

The hot section technology (HOST) dynamic gas temperature measurement system computer program acquires data from two type B thermocouples of different diameters. The analysis method determines the in situ value of an aerodynamic parameter T, containing the heat transfer coefficient from the transfer function of the two thermocouples. This aerodynamic parameter is used to compute a fequency response spectrum and compensate the dynamic portion of the signal of the smaller thermocouple. The...

Topics: NASA Technical Reports Server (NTRS), DYNAMIC CHARACTERISTICS, GAS TEMPERATURE, HEAT TRANSFER...

The objective of this program is to develop an understanding of the fluid mechanics and heat transfer mechanisms that result in the demonstrated performance of the spiral fluted tubing under development at GA Technologies Inc. Particularly emphasized are the processes that result in the augmentation of the heat transfer coefficient without an increase in friction coefficient in the single-phase flow. Quantitative delineation of these processes would allow for their application to the optimal...

Topics: DTIC Archive, Yampolsky,J S, GA TECHNOLOGIES INC SAN DIEGO CA, *HEAT TRANSFER, *FLUID MECHANICS,...

The effects of variable properties on heat transfer in a film-cooled turbulent boundary layer were investigated. A new procedure was developed to deduce adiabatic effectiveness from heat transfer coefficients based on the wall to freestream temperature difference, where both are representative of variable property flow conditions. The new technique was shown to be valid using data from the literature for injection into a turbulent boundary layer from one and two rows of injection holes. From...

Topics: DTIC Archive, Walz,Alfred F , Jr, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *TURBULENT BOUNDARY LAYER,...

This study details the results from experiments conducted to study the heat transfer characteristics during liquid nitrogen spray cooling and pool boiling from a heater array. Four different nozzles at various pressures were used to study the variation in spray cooling heat transfer at liquid nitrogen temperature. Effect of nozzle and flow rate on the critical heat flux and the heat transfer coefficient are presented. This study also provides empirical correlations for the spray cooling...

Topics: DTIC Archive, Chow, L. C., KENTUCKY UNIV LEXINGTON DEPT OF MECHANICAL ENGINEERING, *POWER...

For incompressible benchmark flows, we have demonstrated the capability of the parabolized stability equations (PSE) to simulate the transition process in excellent agreement with microscopic experiments and direct Navier-Stokes simulations at modest computational cost. Encouraged by these results, we have developed the PSE methodology of three-dimensional boundary-layers in general curvilinear coordinates for the range from low to hypersonic speeds, and for both linear and nonlinear problems....

Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER TRANSITION, SIMULATION, INCOMPRESSIBLE FLOW,...

This study investigated the effect of wake passage On the heat transfer in a linear turbine cascade. The apparatus used was the Air-Force Institute of Technology linear Turbine Cascade Test Facility (TCTF). The TCTF was fitted with a be Pulley system to facilitate a series of translating bars. The bars, when passed d upstream of the cascade, created a series of wakes. The parameters varied were freestream model Reynolds number and bar conditions, i.e. , bars in, bars out, and bar passing...

Topics: DTIC Archive, Allen, Kevin S, AIR FORCE FLIGHT TEST CENTER EDWARDS AFB CA, *GAS TURBINES, *WAKE,...

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676

May 6, 2010
05/10

by
Von Glahn, U. H

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Correlation of film-boiling heat transfer coefficients obtained with liquid hydrogen, nitrogen, and freon in forced flow

Topics: FILM BOILING, LIQUID HYDROGEN, LIQUID NITROGEN, FREON, HEAT TRANSFER COEFFICIENTS, HYDROGEN, LIQUID...

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165

Jun 18, 2010
06/10

by
Suksov, I. I

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Determination of friction, recovery, and heat transfer coefficients of two-dimensional laminar boundary layer in compressible gas in vicinity of forward stagnation point

Topics: COEFFICIENT OF FRICTION, LAMINAR BOUNDARY LAYER, STAGNATION POINT, FRICTION, HEAT TRANSFER...

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Jun 20, 2010
06/10

by
LYKOV, A. V.; SMOLSKII, B. M

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CONVECTIVE HEAT EXCHANGE IN HOMOGENEOUS GAS MEDIA, INCLUDING HEAT TRANSFER AND FRICTION RESISTANCE IN PIPES, HYDRODYNAMICS AND HEAT TRANSFER IN JETS, AND INTENSIFICATION OF CONVECTION

Topics: CONVECTIVE HEAT TRANSFER, FLOW RESISTANCE, GAS JETS, HEAT TRANSFER COEFFICIENTS, LAMINAR HEAT...

The effects of curvature and the resulting centrifugal instabilities on local heat transfer distributions are studied in a curved channel at Dean numbers ranging from 50 to 200. The channel has a rectangular cross section of 1.27 cm by 50.1 cm giving an aspect ratio of 40 to 1. Flow is heated in a straight portion of the channel prior to the curved portion in order to obtain flow which is hydrodynamically and thermally fully developed. All baseline tests confirm techniques employed and qualify...

Topics: Curved Heating Channel, Heat Transfer Coefficients, Nusselt Numbers, Dean Vortices, Centrifugal...

This report reviews the state of the art of thermal-hydraulic analysis codes and presents a new code, Program ELM, for analysis of fuel elements. ELM is a concise computational tool for modeling the steady-state thermal-hydraulics of propellant flow through fuel element coolant channels in a nuclear thermal rocket reactor with axial coolant passages. The program was developed as a tool to swiftly evaluate various heat transfer coefficient and friction factor correlations generated for turbulent...

Topics: NASA Technical Reports Server (NTRS), APPLICATIONS PROGRAMS (COMPUTERS), CHANNEL FLOW, COOLING...

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525

May 29, 2011
05/11

by
Saulsberry, R.; Ramirez, J.; Julien, H. L.; Hart, M.; Smith, W.; Bement, L.; Meagher, N. E

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Extensive propulsion and pyrotechnic testing has been in progress at the NASA Johnson Space Center White Sands Test Facility (WSTF) since 1995. This started with the Mars Observer Propulsion and Pyrotechnics Corrective Action Test Program (MOCATP). The MOCATP has concluded, but extensive pyrovalve testing and research and development has continued at WSTF. The capability to accurately analyze and measure pyrovalve combustion product blow-by, evaluate propellant explosions initiated by blow-by,...

Topics: SURFACE TEMPERATURE, HEAT TRANSFER COEFFICIENTS, LAMINAR HEAT TRANSFER, RESEARCH VEHICLES,...

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209

Jun 1, 2011
06/11

by
Cupples, Michael; Green, Shaun; Coverstone, Victori

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Systems analyses were performed for missions utilizing solar electric propulsion systems to deliver payloads to outer-planet destinations. A range of mission and systems factors and their affect on the delivery capability of the solar electric propulsion system was examined. The effect of varying the destination, the trip time, the launch vehicle, and gravity-assist boundary conditions was investigated. In addition, the affects of selecting propulsion system and power systems characteristics...

Topics: TEMPERATURE DISTRIBUTION, HEAT TRANSFER COEFFICIENTS, TURBINE BLADES, GAS TURBINES, TEMPERATURE...

Current reduced-order thermal model for cryogenic propellant tanks is based on correlations built for flat plates collected in the 1950's. The use of these correlations suffers from: inaccurate geometry representation; inaccurate gravity orientation; ambiguous length scale; and lack of detailed validation. The work presented under this task uses the first-principles based Computational Fluid Dynamics (CFD) technique to compute heat transfer from tank wall to the cryogenic fluids, and extracts...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, HEAT TRANSFER COEFFICIENTS,...

The heat transfer coefficient between a molten charge and its surroundings in a Bridgman furnace was determined using an approach utilizing in-situ temperature measurement. The ampoule containing an isothermal melt was suddenly moved from a higher temperature zone to a lower temperature zone. The temperature-time history was used in a lumped-capacity cooling model to evaluate the heat transfer coefficient between the charge and the furnace. The experimentally determined heat transfer...

Topics: NASA Technical Reports Server (NTRS), BRIDGMAN METHOD, DIRECTIONAL SOLIDIFICATION (CRYSTALS),...

Jet impingement cooling of a hypersonic airfoil leading edge is experimentally investigated using thermochromic liquid crystals (TLCS) to measure surface temperature. The experiment uses computer data acquisition with digital imaging of the TLCs to determine heat transfer coefficients during a transient experiment. The data reduction relies on analysis of a coupled transient conduction - convection heat transfer problem that characterizes the experiment. The recovery temperature of the jet is...

Topics: NASA Technical Reports Server (NTRS), JET IMPINGEMENT, CONVECTIVE HEAT TRANSFER, CONDUCTIVE HEAT...

Two- and three-dimensional finite element analyses were performed on uncoated and thermal barrier coated (TBC) silicon nitride plates with and without internal cooling by air. Steady-state heat-transfer analyses were done to optimize the size and the geometry of the cooling channels to reduce thermal stresses, and to evaluate the thermal environment experienced by the plate during burner rig testing. The limited experimental data available were used to model the thermal profile exerted by the...

Topics: NASA Technical Reports Server (NTRS), SILICON NITRIDES, FINITE ELEMENT METHOD, THERMAL STRESSES,...

The film-condensation characteristics of a smooth tube and six externally-finned tubes having fins 1 mm high and 1 mm thick, and ptiches of 1.5, 2.0, 2.5, 3.0, 5.0, and 10.0 mm, were experimentally tested. A smooth copper tube with an active length of 133.5 mm, an outside diameter of 19.05 mm, and an inside diameter of 12.7 mm was first tested to correlate the inside heat-transfer coefficient using the Sieder-Tate equation. The leading coefficient for this equation was found to be 0.034 + or -...

Topics: DTIC Archive, Poole,W M, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *Heat transfer, *Condenser tubes,...

A full-scale model of a double-wedge, simulating a jet vane used in guided missile thrust vector control (TVC), was constructed for subsonic wind tunnel testing to evaluate the feasibility of using a thermal imaging (infrared) system vice thermocouples to determine a surface heat transfer coefficient. The model was preheated, then allowed to cool via forced convection to ambient conditions. Surface temperature readings were taken using thermocouples and a thermal imaging system during the...

Topics: DTIC Archive, Spence,Timothy M, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *WIND TUNNEL TESTS,...