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Technical Paper

Numerical Investigation of Aerodynamic Characteristics on a Blunt Cone Model at Various Angles of Attack under Hypersonic Flow Regimes

2024-06-01
2024-26-0446
The study of aerodynamic forces in hypersonic environments is important to ensure the safety and proper functioning of aerospace vehicles. ...In this paper, computational analysis has been performed on a blunt cone model to study the aerodynamic characteristics when hypersonic flow is allowed to pass through the model. The flow has a Mach number of 8.44 and the angle of attack is varied from 0º to 20º. ...This study helps in understanding the aerodynamic and stability characteristics of hypersonic vehicles at various angles of attack that is significantly different from those of the subsonic or supersonic vehicles.
Standard

High Temperature Pneumatic Duct Systems for Aircraft

2022-03-21
WIP
ARP699F
This Recommended Practice is intended to outline the design, installation, testing, and field maintenance criteria for a high temperature metal pneumatic duct system, for use as a guide in the aircraft industry. These recommendations are to be considered as currently applicable and necessarily subject to revision from time to time, as a result of the rapid development of the industry.
Article

Pratt & Whitney develops digitally curated maintenance solutions for general aviation

2019-07-22
The “Know My PT6” app is a digital gateway to maintenance recommendations and to the services and facilities that P&W offers through its global customer service network for engine maintainers, owners, operators and pilots. It is designed to help PT6 customers and operators optimize the performance and availability of their PT6-powered aircraft.
Standard

Thermodynamics of Incompressible and Compressible Fluid Flow

2019-04-11
CURRENT
AIR1168/1A
The fluid flow treated in this section is isothermal, subsonic, and incompressible. The effects of heat addition, work on the fluid, variation in sonic velocity, and changes in elevation are neglected. An incompressible fluid is one in which a change in pressure causes no resulting change in fluid density. The assumption that liquids are incompressible introduces no appreciable error in calculations, but the assumption that a gas is incompressible introduces an error of a magnitude that is dependent on the fluid velocity and on the loss coefficient of the particular duct section or piece of equipment. Fig. 1A-1 shows the error in pressure drop resulting from assuming that air is incompressible. With reasonably small loss coefficients and the accuracy that is usually required in most calculations, compressible fluids may be treated as incompressible for velocities less than Mach 0.2.
Standard

The Measurement of Engine Thrust in an Altitude Test Facility

2018-02-14
CURRENT
AIR5771A
This report covers engine tests performed in Altitude Test Facilities (ATFs) with the primary purpose of determining steady state thrust at simulated altitude flight conditions as part of the in-flight thrust determination process. As such it is complementary to AIR1703 and AIR5450, published by the SAE E-33 Technical Committee. The gross thrust determined using such tests may be used to generate other thrust-related parameters that are frequently applied in the assessment of propulsion system performance. For example: net thrust, specific thrust, and exhaust nozzle coefficients. The report provides a general description of ATFs including all the major features. These are: Test cell air supply system. This controls the inlet pressure and includes flow straightening, humidity and temperature conditioning. Air inlet duct and slip joint. Note that the report only covers the case where the inlet duct is connected to the engine, not free jet testing.
Standard

High Temperature Pneumatic Duct Systems for Aircraft

2015-11-09
CURRENT
ARP699E
This Recommended Practice is intended to outline the design, installation, testing, and field maintenance criteria for a high temperature metal pneumatic duct system, for use as a guide in the aircraft industry. These recommendations are to be considered as currently applicable and necessarily subject to revision from time to time, as a result of the rapid development of the industry.
Standard

The Measurement of Engine Thrust in an Altitude Test Facility

2015-09-14
HISTORICAL
AIR5771
This report covers engine tests performed in Altitude Test Facilities (ATFs) with the primary purpose of determining steady state thrust at simulated altitude flight conditions as part of the in-flight thrust determination process. As such it is complementary to AIR1703 and AIR5450, published by the SAE E-33 Technical Committee. The gross thrust determined using such tests may be used to generate other thrust-related parameters that are frequently applied in the assessment of propulsion system performance. For example: net thrust, specific thrust, and exhaust nozzle coefficients. The report provides a general description of ATFs including all the major features. These are: Test cell air supply system. This controls the inlet pressure and includes flow straightening, humidity and temperature conditioning. Air inlet duct and slip joint. Note that the report only covers the case where the inlet duct is connected to the engine, not free jet testing.
Magazine

Aerospace Engineering 2011-09-28

2011-09-28
Up in arms over robots As one-armed robots improve in accuracy, gradually expect to see more of them as the pressure grows in aerospace to augment manual labor.
Standard

Aerothermodynamic Systems Engineering and Design

2011-06-20
HISTORICAL
AIR1168/3
This section presents methods and examples of computing the steady-state heating and cooling loads of aircraft compartments. In a steady-state process the flows of heat throughout the system are stabilized and thus do not change with time. In an aircraft compartment, several elements compose the steady-state air conditioning load.
Standard

Thermodynamics of Incompressible and Compressible Fluid Flow

2011-06-20
HISTORICAL
AIR1168/1
The fluid flow treated in this section is isothermal, subsonic, and incompressible. The effects of heat addition, work on the fluid, variation in sonic velocity, and changes in elevation are neglected. An incompressible fluid is one in which a change in pressure causes no resulting change in fluid density. The assumption that liquids are incompressible introduces no appreciable error in calculations, but the assumption that a gas is incompressible introduces an error of a magnitude that is dependent on the fluid velocity and on the loss coefficient of the particular duct section or piece of equipment. Fig. 1A-1 shows the error in pressure drop resulting from assuming that air is incompressible. With reasonably small loss coefficients and the accuracy that is usually required in most calculations, compressible fluids may be treated as incompressible for velocities less than Mach 0.2.
Magazine

Aerospace Engineering & Manufacturing 2008-03-01

2008-03-01
Making an impact in fastening Engineers at Electroimpact help the company get a leg up on the competition in automated fastening. Narrowing in on military requirements UAVs/UCAVs are increasingly important, with the accent on integration- and wider engine choice. Machining and turning centers take center stage Makers of CNC machining equipment are incorporating more and better functionality into their products so users cope better with processing challenges such as those posed by tough new grades of aerospace materials. Open (and often) communication As aircraft companies battle for market share, uniting design and manufacturing teams remains a key challenge.
Magazine

Aerospace Engineering 2006-04-01

2006-04-01
Full throttle for engine solutions Powering aircraft from Mach 2 fighters to tiny hovering UAVs, military engine technology is now operating on a very broad front. Design and production flexibility together with reduced in-service costs are priorities. To the breaking point Test engineers use new rigs and data-acquisition equipment on the latest generation of pneumatics, engines, and airframes. PCs move into the cockpit Pilot training is getting a bit less expensive with the introduction of more portable flight simulations.
Magazine

Aerospace Engineering 2004-06-01

2004-06-01
Showing how it's done Engineers are using software to better manage product development data, and applying tools to a new class of problems. NASA goes deep The agency's new long-term space exploration program starts with a return to the moon and will ultimately enable future exploration of Mars and other solar system destinations. Farnborough preview In an event that happens just once every two years, bringing the multitudes together, it is important to get as much technology as possible into the open and to find solutions to hard problems. Seats under crash loading The FAA and academia have conducted aircraft seat drop tests to compare and contrast passenger crash protection. A fluid approach Aerospace engineers have started using CFD software earlier and earlier in the design process.
Magazine

Aerospace Engineering 2004-05-01

2004-05-01
Advancing the art of manufacturing Use of new manufacturing tools and techniques are allowing aircraft makers to deliver their products faster. A materialistic industry Deciding which material is best suited to construct a part or plane is one of the most complex issues an aerospace engineer faces. Speeding up engine manufacture Fiber optics play a big role in percussion drilling tiny holes.
Technical Paper

Implementation of Parametric Anaylsis to the Aerodynamic Design of a Hypersonic Strike Fighter

2000-10-10
2000-01-5561
A Hypersonic Strike Fighter (HSF) would provide many benefits over current fighters, including increased effectiveness and survivability. ...A parametric method was developed to determine aerodynamic characteristics of hypersonic vehicles in a rapid, automated way. This parametric method and other tools were then used to select a baseline design and optimize this baseline for the notional mission.
Technical Paper

Formulation, Realization, and Demonstration of a Process to Generate Aerodynamic Metamodels for Hypersonic Cruise Vehicle Design

2000-10-10
2000-01-5559
The desire to facilitate the conceptual and preliminary design of hypersonic cruise vehicles has created the need for simple, fast, versatile, and trusted aerodynamic analysis tools. ...Independence, superposition, and scaling properties of the hypersonic engineering method afford an expansive design space without traditional compounding penalties. ...This work postulates the procedure, details the execution, and exposes the results of generating uncompromised aerodynamic metamodels for hypersonic cruise vehicle design.
Technical Paper

Experience and Potential of Multidisciplinary Optimization Tools on Supersonic Aircraft

1997-10-01
975515
The idea of multidisciplinary optimization ( MDO ) has been introduced successfully into wide areas of engineering since the last years. The aircraft industry, especially the preliminary design, was dominated by brilliant personalities up into the seventies. Proposed configurations were designed, built, tested, dropped or a success. This means, that the decision for building an aircraft series was made after successful flight testing. But on one hand due to the pressure of the rising amount of work from more demanding standards which includes more people in the decision process and on the other hand due to more efficient aircraft design tools and performance prediction, the project “go-ahead” tends to go more into the early stages of the hitherto known process of defining civil transport aircraft.
Technical Paper

Mapping Transition on a Hypersonic Vehicle Using Experimental Surface Pressure and Heat Transfer Data

1996-05-01
961315
The comparison of CFD predictions with aerodynamic heating data must be preceded by a careful analysis of the experimental data. Of primary interest is the location of transition since boundary layer state is still a user input for most CFD codes and an error here can result in large variations between the numerical and experimental results. Transition can usually be located by observing the associated sharp rise in surface heating rate with increasing Reynolds number. However, on complex vehicles the distributions of laminar, transitional, and turbulent flow will also be complex, and a rise in heating rate may be produced by flow phenomena other than transition. This paper reviews the method used to determine boundary layer state using experimental surface pressure and heat transfer data.
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