Pitot survey of exhaust flow field of a 2-D scramjet nozzle at Mach 6 with air or freon and argon used for exhaust simulation

A pitot-rake survey of the simulated exhaust of a half-span scramjet nozzle model was conducted in the Langley 20-Inch Mach 6 Tunnel to provide an additional data set for computational fluid dynamics (CFD) code comparisons. A wind-tunnel model was tested with a 26-tube pitot rake that could be manually positioned along the mid-semispan plane of the model. The model configuration had an external expansion surface of 20 degrees and an internal cowl expansion of 12 degrees; tests were also performed with a flow fence. Tests were conducted at a free-stream Reynolds number of approximately 6.5 x 10(exp 6) per foot and a model angle of attack of -0.75 degrees. The two exhaust gas mediums that were tested were air and a Freon 12-argon mixture. Each medium was tested at two jet total pressures at approximately 28 and 14 psia. This document presents the flow-field survey results in graphical as well as tabular form, and several observations concerning the results are discussed. The surveys reveal the major expected flow-field characteristics for each test configuration. For a 50-percent freon 12 and 50-percent argon mixture by volume (Fr-Ar), the exhaust jet pressures were slightly higher than those for air. The addition of a flow fence slightly raised the pitot pressure for the Fr-Ar mixture, but it produced little change for air. For the Fr-Ar exhaust, the plume was larger and the region between the shock wave and plume was smaller

Turbulent boundary layer characteristics of pointed slender bodies of revolution at supersonic speeds

Turbulent boundary layer characteristics of pointed slender bodies of revolution at supersonic speed

Gold(III) mediated biaryl formation of unfunctionalised aromatics and the total sythesis of (±)-polysiphenol

This thesis describes the studies towards the functionalisation of arenes using gold(III) chloride and the total synthesis of (±)-polysiphenol, a naturally occurring bromophenol, isolated from Polysiphonia urceolata, a red alga of the family of Rhodomelaceae found in Chinese coastal waters. The first chapter details the optimisation of the auration reaction of benzene and trapping of the intermediate species, PhAuCl2, with the use of a coordinating ligand. The isolation and characterisation of the aurated species, PhAuCl2.lut, is also discussed. The intermediate aurated species is utilised to achieve oxidative homocoupling, yielding biphenyl. The reaction is further expanded to a number of electron rich and mildly electron deficient aromatics. Attempts to render the reaction catalytic and to achieve oxidative heterocoupling are also described. The second chapter illustrates the total synthesis of (±)-polysiphenol, via a biomimetically inspired highly regioselective intramolecular oxidative coupling route. The two bromine atoms are installed prior to oxidative coupling, preventing further oxidation to a planar aromatized phenanthrene, however attempts to brominate the aromatic rings following oxidative coupling, have also been carried out. The first synthesis of 1,1’-ethane-1,2-diylbis(2,5,6-tribromobenzene-3,4-diol), another natural product belonging to the family of Rhodomelaceae, is also described. The last section of each chapter details the experimental protocols and spectral characterisation of all the compounds synthesised in this study

A parametric experimental investigation of a scramjet nozzle at Mach 6 with Freon and argon or air used for exhaust simulation

A parametric experimental investigation of a scramjet nozzle was conducted with a gas mixture used to simulate the scramjet engine exhaust flow at a free-stream Reynolds number of approximately 6.5 x 10(exp 6) per foot. External nozzle surface angles of 16, 20, and 24 deg were tested with a fixed-length ramp and for cowl internal surface angles of 6 and 12 deg. Pressure data on the external nozzle surface were obtained for mixtures of Freon and argon gases with a ratio of specific heats of about 1.23, which matches that of a scramjet exhaust. Forces and moments were determined by integration of the pressure data. Two nozzle configurations were also tested with air used to simulate the exhaust flow. On the external nozzle surface, lift and thrust forces for air exhaust simulation were approximately half of those for Freon-argon exhaust simulation and the pitching moment was approximately a third. These differences were primarily due to the difference in the ratios of specific heats between the two exhaust simulation gases. A 20 deg external surface angle produced the greatest thrust for a 6 deg cowl internal surface angle. A flow fence significantly increased lift and thrust forces over those for the nozzle without a flow fence

Observations on the Manners and Customs of Eros in Eighteenth Century Edo : The World of Suzuki Harunobu\u27s \u27\u27Fūryū Mane\u27emon\u27\u27

オランダ, ライデン, 1999年10月 27日-29

Pressure drags due to two-dimensional fabrication-type surface roughness on an ogive cylinder at transonic speeds

Pressure drags due to two-dimensional fabrication- type surface roughness on ogive cylinder at transonic speed

Effect of reaction control system jet-flow field interactions on a 0.015 scale model space shuttle orbiter aerodynamic characteristics

The effects of the reaction control system (RCS) jet-flow field interactions on the space shuttle orbiter system during entry are discussed. The primary objective of the test program was to obtain data for the shuttle orbiter configuration to determine control amplification factors resulting from jet interaction between the RCS plumes and the external flow over the vehicle. A secondary objective was to provide data for comparison and improvement of analytic jet interaction prediction techniques. The test program was divided into two phases; (1) force and moment measurements were made with and without RCS blowing, investigating environment parameters (R sub e, Alpha, Beta), RCS plume parameters (Jet pressure ratio, momentum ratio and thrust level), and geometry parameters (RCS pod locations) on the orbiter model, (2) oil flow visualization tests were conducted on a dummy balance at the end of the test

Alternative project delivery in rural Alaska: experiences, quality and claims

Master's Project (M.S.) University of Alaska Fairbanks, 2015The popularity of alternative project delivery systems has expanded beyond the private sector and into the public sector. Alaska embodies unique challenges that may present obstacles while using alternative project delivery systems. This analysis will provide an understanding of alternative project delivery systems in Alaska and how local experiences, quality and claims are affected. Alaska's unique characteristics present both challenges and opportunities for implementing alternative project delivery systems. This report begins with a discussion of experiences from several rural Alaska projects, and how alternative project delivery systems can be utilized. Some impacts that alternative project delivery systems have on quality are then presented, including a perspective on quality and recommendations for achieving customer satisfaction. A treatment of construction claims is then provided, followed by conclusions and recommendations for stakeholders in selecting an appropriate project delivery system. Alternative project delivery systems were researched by means of scholarly literature reviews, professional interviews and seminars. The report of these findings is intended to provide owners and contractors with a concise presentation of the challenges and advantages for using alternative project delivery systems in Alaska

Considerations regarding the evaluation and reduction of supersonic skin friction

Experimental and predicted data on turbulent boundary-layer skin friction of supersonic transport configuratio

Turbulent Skin Friction at High Reynolds Numbers and Low Supersonic Velocities

Turbulent skin friction at high Reynolds number and low supersonic speed