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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

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.
Standard

Spacecraft Life Support Systems

2011-06-20
HISTORICAL
AIR1168/14
A life support system (LSS) is usually defined as a system that provides elements necessary for maintaining human life and health in the state required for performing a prescribed mission. The LSS, depending upon specific design requirements, will provide pressure, temperature, and composition of local atmosphere, food, and water. It may or may not collect, dispose, or reprocess wastes such as carbon dioxide, water vapor, urine, and feces. It can be seen from the preceding definition that LSS requirements may differ widely, depending on the mission specified, such as operation in Earth orbit or lunar mission. In all cases the time of operation is an important design factor. An LSS is sometimes briefly defined as a system providing atmospheric control and water, waste, and thermal management.
Standard

Spacecraft Life Support Systems

2012-10-15
CURRENT
AIR1168/14A
A life support system (LSS) is usually defined as a system that provides elements necessary for maintaining human life and health in the state required for performing a prescribed mission. The LSS, depending upon specific design requirements, will provide pressure, temperature, and composition of local atmosphere, food, and water. It may or may not collect, dispose, or reprocess wastes such as carbon dioxide, water vapor, urine, and feces. It can be seen from the preceding definition that LSS requirements may differ widely, depending on the mission specified, such as operation in Earth orbit or lunar mission. In all cases the time of operation is an important design factor. An LSS is sometimes briefly defined as a system providing atmospheric control and water, waste, and thermal management.
Standard

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.
Standard

NBC Protection Considerations for ECS Design

2014-07-01
CURRENT
AIR4362A
This SAE Aerospace Information Report (AIR) provides Nuclear, Biological and Chemical (NBC) protection considerations for environmental control system (ECS) design. It is intended to familiarize the ECS designer with the subject in order to know what information will be required to do an ECS design where NBC protection is a requirement. This is not intended to be a thorough discussion of NBC protection. Such a document would be large and would be classified. Topics of NBC protection that are more pertinent to the ECS designer are discussed in more detail. Those of peripheral interest, but of which the ECS designer should be aware are briefly discussed. Only radiological aspects of nuclear blast are discussed. The term CBR (Chemical, Biological, and Radiological) has been used to contrast with NBC to indicate that only the radiological aspects of a nuclear blast are being discussed.
Standard

NBC Protection Considerations for ECS Design

2008-08-19
HISTORICAL
AIR4362
This SAE Aerospace Information Report (AIR) provides Nuclear, Biological and Chemical (NBC) protection considerations for environmental control system (ECS) design. It is intended to familiarize the ECS designer with the subject in order to know what information will be required to do an ECS design where NBC protection is a requirement. This is not intended to be a thorough discussion of NBC protection. Such a document would be large and would be classified. Topics of NBC protection that are more pertinent to the ECS designer are discussed in more detail. Those of peripheral interest, but of which the ECS designer should be aware are briefly discussed. Only radiological aspects of nuclear blast are discussed. The term CBR (Chemical, Biological, and Radiological) has been used to contrast with NBC to indicate that only the radiological aspects of a nuclear blast are being discussed.
Standard

Liquid Cooling Systems

2016-09-10
WIP
AIR1811B
The purpose of this Aerospace Information Report (AIR) is to provide guidelines for the selection and design of airborne liquid cooling systems. This publication is applicable to liquid cooling systems of the closed loop type and the expendable coolant type in which the primary function is transporting of heat from its source to a heat sink. Most liquid cooling system applications are oriented toward the cooling of electronics. Liquid cooling techniques, heat sinks, design features, selection of coolants, corrosion control, and servicing requirements for these systems are presented. Information on vapor compression refrigeration systems, which are a type of cooling system, is found in Reference 1.
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.
Standard

Heater and Accessories, Aircraft Internal Combustion Heat Exchanger Type

2023-05-10
WIP
AS8040D
This SAE Aerospace Standard (AS) covers combustion heaters and accessories used in, but not limited to, the following applications: a. Cabin heating (all occupied regions and windshield heating) b. Wing and empennage anti-icing c. Engine and accessory heating (when heater is installed as part of the aircraft) d. Aircraft deicing
Standard

Heat and Mass Transfer and Air-Water Mixtures

2007-12-03
HISTORICAL
AIR1168/2
Heat transfer is the transport of thermal energy from one point to another. Heat is transferred only under the influence of a temperature gradient or temperature difference. The direction of heat transfer is always from the point at the higher temperature to the point at the lower temperature, in accordance with the second law of thermodynamics. The fundamental modes of heat transfer are conduction, convection, and radiation. Conduction is the net transfer of energy within a fluid or solid occurring by the collisions of molecules, atoms, or electrons. Convection is the transfer of energy resulting from fluid motion. Convection involves the processes of conduction, fluid motion, and mass transfer. Radiation is the transfer of energy from one point to another in the absence of a transporting medium. In practical applications several modes of heat transfer occur simultaneously.
Standard

Heat and Mass Transfer and Air-Water Mixtures

2011-07-25
CURRENT
AIR1168/2A
Heat transfer is the transport of thermal energy from one point to another. Heat is transferred only under the influence of a temperature gradient or temperature difference. The direction of heat transfer is always from the point at the higher temperature to the point at the lower temperature, in accordance with the second law of thermodynamics. The fundamental modes of heat transfer are conduction, convection, and radiation. Conduction is the net transfer of energy within a fluid or solid occurring by the collisions of molecules, atoms, or electrons. Convection is the transfer of energy resulting from fluid motion. Convection involves the processes of conduction, fluid motion, and mass transfer. Radiation is the transfer of energy from one point to another in the absence of a transporting medium. In practical applications several modes of heat transfer occur simultaneously.
Standard

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.
Standard

General Requirements for Application of Vapor Cycle Refrigeration Systems for Aircraft

1997-10-01
HISTORICAL
ARP731B
Recommendations of this ARP refer specifically to the application of closed cycle vapor cycle refrigeration systems as a source of cooling in an aircraft air conditioning system. General recommendations for an air conditioning system which may include a vapor cycle system as a cooling source are included in ARP85, Air Conditioning Equipment, General Requirements for Subsonic Airplanes, ARP292, Air Conditioning, Helicopters, General Requirements For, and AIR806, Air Conditioning Design Information for Cargo and High Density Passenger Transport Airplanes, and are not included herein. Vapor cycle refrigeration system design recommendations are presented in this ARP in the following general areas: a SYSTEM Design Recommendations: (See Section 3) b COMPONENT Design Recommendations: (See Section 4) c Desirable Design Features: (See Section 5)
Standard

GUIDE FOR QUALIFICATION TESTING OF AIRCRAFT AIR VALVES

1982-10-01
HISTORICAL
ARP986A
This document defines tests to be performed on electrically, pneumatically, and mechanically actuated (regulating, modulating, and shutoff) air valves. The valves may be further defined as those which function in response to externally applied forces or in response to variations in upstream and/or downstream duct air conditions to maintain a calibrated duct air condition (i.e., air flow, air pressure, air temperature, air pressure ratio, etc.). The requirements of this document should govern for all qualification tests unless different requirements are established by the detail specifications.
Standard

GUIDE FOR QUALIFICATION TESTING OF AIRCRAFT AIR VALVES

1968-11-01
HISTORICAL
ARP986
This document defines the tests to be performed on electrically, pneumatically, and mechanically actuated (regulating, modulating, and shutoff) air valves. The valves may be further defined as those which function in response to externally applied forces or in response to variations in upstream and/or downstream duct air conditions to maintain a calibrated duct air condition (i. e., air flow, air pressure, air temperature, air pressure ratio, etc. ). The requirements of this document should govern for all qualification tests unless different requirements are established by the detail specifications.
Standard

GENERAL REQUIREMENTS FOR APPLICATION OF VAPOR CYCLE REFRIGERATION SYSTEMS FOR AIRCRAFT

1973-04-15
HISTORICAL
ARP731A
Recommendations of this ARP refer specifically to the application of closed cycle vapor cycle refrigeration systems as a source of cooling in an aircraft air conditioning system. General recommendations for an air conditioning system which may include a vapor cycle system as a cooling source are included in ARP 85, Air Conditioning Equipment, General Requirements for Subsonic Airplanes, ARP 292, Air Conditioning, Helicopters, General Requirements For, and AIR 806, Air Conditioning Design Information for Cargo and High Density Passenger Transport Airplanes, and are not included herein.
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