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Thermophysical Properties of the Natural Environment, Gases, Liquids, and Solids

2004-06-22
HISTORICAL
AIR1168/9
This AIR is arranged in the following four sections: 2A - Properties of the Natural Environment 2B - Properties of Gases 2C - Properties of Liquids 2D - Properties of Solids A summary of each section is given below. Section 2A - This section includes currently applicable earth atmosphere standards (Refs. 101 and 103) and data on the near-Earth environment. Limited data on Mars and Venus reflected solar and planetary-emitted radiation and on micrometeorite data are also included. For space vehicle applications, environmental models are of two general types: orbital and reentry. For orbital models, variable properties such as time and solar flux are usually averaged. Reentry atmospheres are chiefly a function of location and altitude, and selection may be based on reentry location. Variation with latitude is an important local effect (Ref. 106). The electromagnetic solar radiation data in this section are for altitudes above the Earth’s atmosphere.
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Thermophysical Characteristics of Working Fluids and Heat Transfer Fluids

2017-05-19
CURRENT
AIR1168/10A
This AIR is arranged in the following two sections: 2E - Thermodynamic Characteristics of Working Fluids, which contains thermodynamic diagrams for a number of working fluids currently in use and supplied by various industrial firms. 2F - Properties of Heat Transfer Fluids, which contains data, primarily in graphical form, on fluids that are frequently used in fluid heat transfer loops. Other properties of the environment, gases, liquids, and solids, can be found, as follows, in AIR1168/9: 2A-Properties of the Natural Environment 2B-Properties of Gases 2C-Properties of Liquids 2D-Properties of Solids
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The Advanced Environmental Control System (AECS) Computer Program for Steady State Analysis and Preliminary System Sizing

2003-10-31
HISTORICAL
AIR1706B
Many different computer programs have been developed to determine performance capabilities of aircraft environmental control systems, and to calculate size and weight tradeoffs during preliminary design. Many of these computer programs are limited in scope to a particular arrangement of components for a specific application. General techniques, providing flexibility to handle varied types of ECS configurations and different requirements (i.e., during conceptual or preliminary design, development, testing, production, and operation) are designated “company proprietary” and are not available for industry-wide use. This document describes capabilities, limitations, and potentials of a particular computer program which provides a general ECS analysis capability, and is available for use in industry. This program, names AECS1, was developed under the sponsorship of the U.S. Air Force Flight Dynamics Laboratory (References 1 and 2).
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THERMOPHYSICAL CHARACTERISTICS OF WORKING FLUIDS AND HEAT TRANSFER FLUIDS

2011-06-21
HISTORICAL
AIR1168/10
This AIR is arranged in the following two sections: 2E - Thermodynamic Characteristics of Working Fluids, which contains thermodynamic diagrams for a number of working fluids currently in use and supplied by various industrial firms. 2F - Properties of Heat Transfer Fluids, which contains data, primarily in graphical form, on fluids that are frequently used in fluid heat transfer loops. Other properties of the environment, gases, liquids, and solids, can be found, as follows, in AIR1168/9: 2A-Properties of the Natural Environment 2B-Properties of Gases 2C-Properties of Liquids 2D-Properties of Solids
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THE ADVANCED ENVIRONMENTAL CONTROL SYSTEM (AECS) COMPUTER PROGRAM FOR STEADY STATE ANALYSIS AND PRELIMINARY SYSTEM SIZING

1986-10-01
HISTORICAL
AIR1706A
Many different computer programs have been developed to determine performance capabilities of aircraft environmental control systems, and to calculate size and weight tradeoffs during preliminary design. Many of these computer programs are limited in scope to a particular arrangement of components for a specific application. General techniques, providing flexibility to handle varied types of ECS configurations and different requirements (i.e., during conceptual or preliminary design, development, testing, production, and operation) are designated "company proprietary" and are not available for industry-wide use. This document describes capabilities, limitations, and potentials of a particular computer program which provides a general ECS analysis capability, and is available for use in industry. This program, names AECS1, was developed under the sponsorship of the U.S. Air Force Flight Dynamics Laboratory (References 1 and 2).
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Spacecraft Equipment Environmental Control

2011-07-25
CURRENT
AIR1168/13A
This part of the manual presents methods for arriving at a solution to the problem of spacecraft inflight equipment environmental control. The temperature aspect of this problem may be defined as the maintenance of a proper balance and integration of the following thermal loads: equipment-generated, personnel-generated, and transmission through external boundary. Achievement of such a thermal energy balance involves the investigation of three specific areas: 1 Establishment of design requirements. 2 Evaluation of properties of materials. 3 Development of analytical approach. The solution to the problem of vehicle and/or equipment pressurization, which is the second half of major environmental control functions, is also treated in this section. Pressurization in this case may be defined as the task associated with the storage and control of a pressurizing fluid, leakage control, and repressurization.
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Spacecraft Boost and Entry Heat Transfer

2008-02-19
HISTORICAL
AIR1168/11
The prediction of vehicle temperatures during ascent through the earth’s atmosphere requires an accurate knowledge of the aerodynamic heating rates occurring at the vehicle surface. Flight parameters required in heating calculations include the local airstream velocity, pressure, and temperature at the boundary layer edge for the vehicle location in question. In addition, thermodynamic and transport air properties are required at these conditions. Both laminar and turbulent boundary layers occur during the boost trajectory. Experience has shown that laminar and turbulent heating are of equivalent importance. Laminar heating predominates in importance in the stagnation areas, but the large afterbody surfaces are most strongly affected by turbulent heating. Once the local flow conditions and corresponding air properties have been obtained, the convective heating rate may be calculated for a particular wall temperature.
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Spacecraft Boost and Entry Heat Transfer

2011-07-25
CURRENT
AIR1168/11A
The prediction of vehicle temperatures during ascent through the earth’s atmosphere requires an accurate knowledge of the aerodynamic heating rates occurring at the vehicle surface. Flight parameters required in heating calculations include the local airstream velocity, pressure, and temperature at the boundary layer edge for the vehicle location in question. In addition, thermodynamic and transport air properties are required at these conditions. Both laminar and turbulent boundary layers occur during the boost trajectory. Experience has shown that laminar and turbulent heating are of equivalent importance. Laminar heating predominates in importance in the stagnation areas, but the large afterbody surfaces are most strongly affected by turbulent heating. Once the local flow conditions and corresponding air properties have been obtained, the convective heating rate may be calculated for a particular wall temperature.
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OZONE PROBLEMS IN HIGH ALTITUDE AIRCRAFT

1996-07-01
HISTORICAL
AIR910A
The purpose of this report is to provide information on ozone and its control in high altitude aircraft environmental systems. Sources of this information are listed in the selected bibliography appearing at the end of this report, to which references are made throughout.
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Jet Blast Windshield Rain Removal Systems for Commercial Transport Aircraft

2008-11-06
HISTORICAL
AIR805B
The purpose of this information report is to present factors which affect the design and development of jet blast windshield rain removal systems for commercial transport aircraft. A satisfactory analytical approach to the design of these systems has not yet been developed. Although detailed performance data are available for some test configurations, rain removal systems will generally be unique to specific aircraft. This, then, requires a preliminary design for the system based on available empirical data to be followed with an extensive laboratory development program.
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HEAT TRANSFER PROBLEMS ASSOCIATED WITH AEROSPACE VEHICLES

1978-04-01
CURRENT
AIR732
The discipline of heat transfer concerns itself basically with the three modes of transferring thermal energy (convection, conduction, and radiation) and their inter-relations. In any phase of aerospace vehicle design, the importance of any of these basic modes will vary depending upon the natural and induced environment the mission imposes as well as the vehicle configuration.
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GUIDE FOR PREPARING AN ECS COMPUTER PROGRAM USER'S MANUAL

1980-06-01
HISTORICAL
ARP1623
These recommendations apply to the user's manual for any computer program pertaining to aircraft ECS. This includes computer programs for: a Cabin air conditioning and pressurization performance. b Avionics equipment cooling system performance. c Engine bleed air system performance. d Compartment and equipment thermal analysis. e Environmental protection system performance. These recommendations apply to user's manuals for generalized computer programs as well as those for a specific component or system.
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Environmental Control Systems Life Cycle Cost

2017-02-07
CURRENT
AIR1812B
This report contains background information on life cycle cost elements and key ECS cost factors. Elements of life cycle costs are defined from initial design phases through operational use. Information on how ECS designs affect overall aircraft cost and information on primary factors affecting ECS costs are discussed. Key steps or efforts for comparing ECS designs on the basis of LCC are outlined. Brief descriptions of two computer programs for estimating LCC of total aircraft programs and their use to estimate ECS LCC, are included.
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Environmental Control Systems Life Cycle Cost

2010-01-20
HISTORICAL
AIR1812A
This report contains background information on life cycle cost elements and key ECS cost factors. Elements of life cycle costs are defined from initial design phases through operational use. Information on how ECS designs affect overall aircraft cost and information on primary factors affecting ECS costs are discussed. Key steps or efforts for comparing ECS designs on the basis of LCC are outlined. Brief descriptions of two computer programs for estimating LCC of total aircraft programs and their use to estimate ECS LCC, are included.
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Engineering Analysis System (EASY) Computer Program for Dynamic Analysis of Aircraft ECS

2003-10-31
HISTORICAL
AIR1823A
The Engineering Analysis SYstem (EASY) computer program is summarized in this report. It provides techniques for analysis of steady-state and dynamic (transient) environmental control system (ECS) performance, control system stability, and for synthesis of optimal ECS. General uses of a transient analysis computer program for ECS design and development, and general features of EASY relative to these uses, are presented. This report summarizes the nine analysis options of EASY, EASY program organization for analyzing ECS, data input to the program and resulting data output, and a discussion of EASY limitations. Appendices provide general definitions for dynamic analysis, and samples of input and output for EASY.
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ENVIRONMENTAL CONTROL SYSTEMS LIFE CYCLE COST

1985-10-01
HISTORICAL
AIR1812
This report contains background information on life cycle cost elements and key ECS cost factors. Elements of life cycle costs are defined from initial design phases through operational use. Information on how ECS designs affect overall aircraft cost and information on primary factors affecting ECS costs are discussed. Key steps or efforts for comparing ECS designs on the basis of LCC are outlined. Brief descriptions of two computer programs for estimating LCC of total aircraft programs and their use to estimate ECS LCC, are included.
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ENVIRONMENTAL CONTROL SYSTEM TRANSIENT ANALYSIS COMPUTER PROGRAM (EASY)

2011-08-10
HISTORICAL
AIR1823
The Environmental Control Analysis SYstem (EASY) computer program is summarized in this report. Development of this computer program initially was sponsored by the U.S. Air Force Flight Dynamics Laboratory. (See References 1, 2, 3, and 4.) It provides techniques for determination of steady state and dynamic (transient) ECS performance, and of control system stability; and for synthesis of optimal ECS control systems. The program is available from the U.S. Air Force, or as a proprietary commercial version. General uses of a transient analysis computer program for ECS design and development, and general features of EASY relative to these uses, are presented. This report summarizes the nine analysis options of EASY, EASY program organization for analyzing ECS, data input to the program and resulting data output, and a discussion of EASY limitations. Appendices provide general definitions for dynamic analysis, and samples of input and output for EASY.
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