scholarly journals NNEPEQ—Chemical Equilibrium Version of the Navy/NASA Engine Program

1989 ◽  
Vol 111 (1) ◽  
pp. 114-116 ◽  
Author(s):  
L. H. Fishbach ◽  
S. Gordon
Keyword(s):  
High Temperature ◽  
Chemical Equilibrium ◽  
Computer Code ◽  
Turbine Engines ◽  
Government Agencies ◽  
Gas Generator ◽  
Engine Component ◽  
High Mach ◽  
Alternate Fuels ◽  
Component Models

The Navy NASA Engine Program, NNEP, developed in 1975, currently is in use at a large number of government agencies, commercial companies, and universities. This computer code has been used extensively to calculate the design and off-design (matched) performance of a broad range of turbine engines, ranging from subsonic turboprops to variable cycle engines for supersonic transports. Recently, there has been increased interest in applications that NNEP was not capable of simulating, namely, high Mach applications, alternate fuels including cryogenics, and cycles such as the gas generator air-turbo-rocket (ATR). In addition, there is interest in cycles employing ejectors such as for military fighters. New engine component models had to be created for incorporation into NNEP, and it was also found necessary to include chemical dissociation effects of high-temperature gases. This paper discusses the incorporation of these extended capabilities of NNEP and illustrates some of the effects of these changes.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

HAYNES ALLOY 75

Alloy Digest ◽  
1999 ◽  
Vol 48 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Heat Treating ◽  
Turbine Engines ◽  
Chromium Alloy ◽  
Gas Turbine Engines ◽  
Typical Application ◽  
Good Oxidation Resistance ◽  
Temperature Performance ◽  
Haynes Alloy

Abstract Haynes alloy 75 is an 80 nickel-20 chromium alloy with both good oxidation resistance and good mechanical properties at high temperatures. It is amenable to all forms of fabrication and welding. A typical application for sheet metal is fabrications in gas turbine engines. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming and heat treating. Filing Code: Ni-557. Producer or source: Haynes International Inc.

Operating Degradations of Air Turbine Scoops of Turbo-Engines

2009 ◽  
Vol 147-149 ◽  
pp. 524-529 ◽  
Author(s):  
Andrzej Szczepankowski ◽  
Janusz Szymczak ◽  
Jaroslaw Spychała
Keyword(s):  
High Temperature ◽  
Early Detection ◽  
Turbine Engines ◽  
Operating Process ◽  
Air Turbine ◽  
High Temperature Erosion

The paper presents various types of turbine scoops damages that are being found in the operating process of air turbine engines (TSO). When dividing them, having in mind a genesis of their origin, a special attention has been paid to corrosion and high-temperature erosion, often being a reason for destruction of the entire unit. The damages hereto described have been illustrated with examples collected during endoscope surveys of TSO internal spaces or their post-failure disassembly. The summary points out to the ways and directions of works aiming at early detection of TSO turbines units damages, and thus at improvement of their operating safety.

High Temperature Engine Component Exploratory Design Development

1989 ◽  
Author(s):  
Walter Bryzik ◽  
Melvin E. Woods ◽  
Ernest Schwarz ◽  
Paul Glance
Keyword(s):  
High Temperature ◽  
Design Development ◽  
Engine Component

scholarly journals Standard Measurement of Aircraft Gas Turbine Engine Exhaust Smoke

1971 ◽  
Author(s):  
D. L. Champagne
Keyword(s):  
Federal Government ◽  
Gas Turbine ◽  
Unit Volume ◽  
Standard System ◽  
Turbine Engines ◽  
Government Agencies ◽  
Engine Exhaust ◽  
Turbine Engine ◽  
Standard Measurement ◽  
Definition Of

A standard system (equipment and procedures) for measuring smoke emitted by aircraft turbine engines has been developed. It has been adopted by several Federal Government agencies. In this paper, the system is explained and its accuracy defined. An experimentally determined relationship between the system’s parameters and true smoke density (weight of solids per unit volume) is presented and theoretically examined. The definition of smoke plume visibility in terms of the system’s parameters is also developed. This work led to the conclusion that aircraft turbine engine exhaust smoke is composed of two groups of particles: the very small, which are primarily responsible for visible obscuration, and larger particles, which may constitute as much as half of the total by weight, but do not appreciably contribute to plume visibility.

Misbehavior in High Temperature Equilibrium of Water-Gas Reaction

2012 ◽  
Vol 245 ◽  
pp. 346-351
Author(s):  
Radu Dan Rugescu ◽  
Florin Radu Bacaran
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Chemical Equilibrium ◽  
Solid Propellant ◽  
Combustion Products ◽  
Linearization Method ◽  
Gaseous Products ◽  
Direct Linearization ◽  
Temperature Equilibrium ◽  
Water Gas

The observation that the chemical equilibrium between the combustion products of solid propellant samples within static calorimeters is unexpectedly freezing at high temperatures is proved through a general numerical simulation of the isochoric cooling with chemical reactions between the gaseous products. A proprietary, direct linearization method of thermochemical computation is used that enables following any chemical reaction in equilibrium with high convergence. The observed chemical freezing within calorimeters is proved.

A Dual Flow High Mach Number Centrifugal Compressor for a Small Gas Turbine APU

2011 ◽  
Author(s):  
Colin Rodgers ◽  
Dan Brown
Keyword(s):  
Gas Turbine ◽  
Centrifugal Compressor ◽  
Test Performance ◽  
Development Program ◽  
Compressed Air ◽  
Gas Generator ◽  
Electric Generator ◽  
Core Module ◽  
Auxiliary Power Units ◽  
High Mach

Small gas turbine auxiliary power units (APU’s) of conventional load compressor type wherein the gas generator or core module directly drives a separate centrifugal load compressor are installed in aircraft and helicopters to supply both compressor air for main engine starting and air conditioning combined with shaft power to drive an electric generator. This paper describes the test development of a dual flow centrifugal compressor (DFC) where the impeller flow was split into two streams, the inner (hub) stream supplying compressed air to the gas generator core module, and the outer (DFB) bleed stream delivering a compressed air to the aircraft pneumatic power system. DFC development rig testing revealed that the hub or core stream satisfied compressor design requirements but that the DFB stream flowpath demonstrated unstable characteristics with decreasing efficiency as test speeds were increased. At the time of the development program in the early 1990’s convergence difficulties were encountered with CFD attempts to corroborate the test results, and thus pinpoint plausible explanations, as a consequence a renewed upgraded 2010 CFD analysis of the dual flow compressor is presented herein confirming the test performance characteristics of both flow streams and the fundamental reason for poor DFB performance as excessive diffusion at high relative Mach numbers.

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