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Some of the specific areas associated with straight jet and turboprop engine installations are outlined where drag reduction and, thus, improved aircraft system performance is obtained. Specific areas constitute air intake sizing for general aviation aircraft, exhaust duct geometries and cooling system arrangements for propeller powered aircraft.
A device for installing rocket engines is reported that is supported at a cant relative to vertical by an axially extensible, tiltable pedestal. A lifting platform supports the rocket engine at its thrust chamber exit, including a mount having a concentric base characterized by a concave bearing surface, a plurality of uniformly spaced legs extended radially from the base, and an annular receiver coaxially aligned with the base and affixed to the distal ends of said legs for receiving the thrust chamber exit. The lifting platform rests on a seat concentrically related to the pedestal and affixed to an extended end portion thereof having a convex bearing surface mated in sliding engagement with the concave bearing surface of the annular base for accommodating a rocking motion of the platform.
The approach and takeoff performance was evaluated of a contracting cowl variable geometry design inlet installed on a high-bypass-ratio turbofan engine. The design was finalized after consideration of aerodynamic, acoustic, and mechanical factors which would lead to a viable flight worthy concept. The aerodynamic results are presented in terms of inlet recovery and distortion parameter as functions of throat Mach number, and acoustic results in terms of Perceived Noise Level. The contracting cowl high throat Mach number inlet is shown to be an attractive means to reduce forward radiated noise from a high bypass ratio turbofan engine.
The purpose of this experimental program was to evaluate the approach and takeoff performance of a contracting cowl variable geometry design inlet installed on a high-bypass-ratio turbofan engine. The design was finalized after consideration of aerodynamic, acoustic, and mechanical factors which would lead to a viable flight-worthy inlet concept. The aerodynamic results are presented in terms of inlet recovery and distortion parameter as functions of throat Mach number, and acoustic results in terms of Perceived Noise Level. The contracting cowl high throat Mach number inlet is shown to be an attractive means to reduce forward radiated noise from a high bypass ratio turbofan engine.
Tiny vise simplifies installation of cable clamps in confined spaces. As thumbscrew is tightened, ears of clamps are forced together, and bolt passes through all lugs and into hole in stationary jaw.
The amount of nitrogen oxides introduced into the atmosphere by gas turbines is very significant in relation to the total amount of nitrogen oxide emissions produced by chemical installations and combustion engines. Turbine manufacturers are therefore working to develop combustion chambers with sufficiently low nitrogen oxide emission concentrations. Attention is given to aspects of nitrogen oxide formation in gas turbines, the parameters which determine this formation, and suitable approaches to reducing nitrogen oxide emissions.
An investigation has been conducted in the Langley 16-foot transonic tunnel to determine nozzle/afterbody performance of nonaxisymmetric nozzles installed in a 1/12-scale F-15 propulsion model. Tests were performed at Mach numbers from 0.60 to 1.20 at angles-of-attack from -2 to +9 deg and jet-total-pressure ratios from 1.0 (jet-off) to 5.0, depending on Mach number. The baseline F-15 afterbody was tested with axisymmetric nozzles, and two different two-dimensional wedge nozzle afterbody designs. Results of this investigation indicate that one of the two-dimensional afterbody designs had lower drag than the baseline at a Mach number of 1.20, and about the same drag for subsonic Mach numbers at scheduled nozzle pressure ratios. Thrust vectoring of the two-dimensional wedge nozzles produced significant induced lift on the afterbody and horizontal tails, while thrust reversing had little effect on horizontal tail effectiveness.
Various factors contributing to the high drag caused by the installation of a six-module scramjet engine were determined from wind tunnel tests at Mach numbers from 0.2 to 0.7. Methods for alleviating this drag were also explored. The external exhaust nozzle, required for good cruise performance, was a major contributor. Of the drag produced by the engine modules, a significant fraction was attributable to wall divergence in the combustor. Good drag simulation could be achieved by using a single fuel injection strut having approximately the same cross-sectional area as the three used on the full-scale engine. External exhaust nozzle fences had a small but beneficial effect on maximum L/D and a flap which diverted the flow away from the inlet was effective in decreasing drag but only at low angles of attack.
Manual for prototype solar-heating system gives detailed installation procedures for each of seven subsystems. Procedures for operation and maintenance are also included. It discusses architectural considerations, building construction considerations, and checkout-test procedures.
Package covers installation, operation, and maintenance of heat exchanger which has auxiliary heaters that provide backup heat in inclement weather. Drawings, including schematics, complement text material, which is organized as step-by-step instructions. Trouble-shooting section discusses probable causes and repairs for most common difficulties.
Installation guidelines for architects and engineers discussing solar-heating system built in Togus, Maine are presented. Includes brief, functional description of system and summary of operation. Drawings complement text.
Report presents performance, installation, operation, and maintenance information for flat-plate liquid solar energy collector. Methods for determining optimum collector sizing are described as well.
Report contains general description of concentrating solar collector and tracking system kit, along with comprehensive drawings, instructions, and guidelines to assist in field assembly, installation, operation, and maintenance of system.
Procedures for installing, operating, and maintaining a programmable control system which utilizes a F8 microprocessor to perform all timing, control, and calculation functions in order to customize system performance to meet individual requirements for solar heating, combined heating and cooling, and/or hot water systems are described. The manual discusses user configuration and options, displays, theory of operation, trouble-shooting procedures, and warranty and assistance. Wiring lists, parts lists, drawings, and diagrams are included.
This report consists of details for the installation, operation and maintenance of a prototype heating and hot water system, designed for residential or light commercial applications. This system consists of the following subsystems: air type collectors, pebble bed thermal storage, air handling unit, air to water heat exchanger, hot water preheat tank, auxiliary energy, ducting system.
The installation, operation and maintenance of the Maxi-Therm S-101 Thermosypnon Heating Module is described. The Maxi-Therm S-101 is a packaged unit, complete with air filter, blower, electrical controls, and a thermosyphon liquid to air heat exchanger. It is intended for use in residential solar heating systems and can utilize off-peak electrical power.
The Site Data Acquisition Subsystem (SDAS) Mod 1 was designed to collect sensor measurement data from solar energy demonstration site. This report provides a brief description of the SDAS and defines the installation requirements and procedures, the operations description and the procedures for field maintenance of the subsystem.
The prototype system 2 solar hot water was designed for use in a single family dwelling and consists of the following subsystems: collector, storage, energy transport, and control. Guidelines are presented for utilization in the development of detailed installation plans and specifications. Instruction on operation, maintenance, and repair of the system is discussed.