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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
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

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 Control of Excess Humidity in Avionics Cooling

2020-05-12
CURRENT
ARP987B
This Aerospace Recommended Practice (ARP) outlines the causes and impacts of moisture and/or condensation in avionics equipment and provides recommendations for corrective and preventative action.
Standard

Testing of Airplane Installed Environmental Control Systems (ECS)

2021-12-27
CURRENT
ARP217D
This document deals with ground and flight test of airplane installed Environmental Control Systems (ECS), Figure 1. The ECS provide an environment, controlled within specified operational limits of comfort and safety, for humans, animals, and equipment. These limits include the following: pressure, temperature, humidity, ventilation air velocity, ventilation rate, wall temperature, audible noise, vibration, and environment composition (ozone, contaminants, etc.). The ECS are composed of equipment, controls, and indicators that supply, distribute, recycle and exhaust air to maintain the desired environment.
Standard

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
Standard

TESTING OF PROTOTYPE AIRPLANE AIR CONDITIONING SYSTEMS

1951-03-15
HISTORICAL
ARP217
These recommendations are written to cover the testing of air conditioning equipment as installed in the prototype aircraft for the purpose of: A Demonstrating safety of the installation. B Demonstrating performance of the installation. a Aircraft ducting and distribution system. b Component parts (i.e., vendors equipment) C Obtaining data for future design.
Standard

TEMPERATURE CONTROL EQUIPMENT, AUTOMATIC AIRPLANE CABIN

1943-01-01
HISTORICAL
ARP89
These specifications are written to cover automatic temperature controls under three classifications, namely: A AUTOMATIC TEMPERATURE CONTROLS - GENERAL - Dealing with features applicable to all types and uses. B AUTOMATIC TEMPERATURE CONTROLS - MILITARY AND COMMERCIAL - Covering features applicable to military aircraft and commercial aircraft. C DESIRABLE DESIGN FEATURES - General information for use of those concerned in meeting the requirements contained herein.
Standard

Spacecraft Thermal Balance

2004-09-08
HISTORICAL
AIR1168/12
In the design of spacecraft, heat transfer becomes a criterion of operation to maintain structural and equipment integrity over long periods of time. The spacecraft thermal balance between cold space and solar, planetary, and equipment heat sources is the means by which the desired range of equipment and structural temperatures are obtained. With the total spacecraft balance set, subsystem and component temperatures can be analyzed for their corresponding thermal requirements. This section provides the means by which first-cut approximations of spacecraft surface, structure, and equipment temperatures may be made, using the curves of planetary and solar heat flux in conjunction with the desired coating radiative properties. Once the coating properties have been determined, the material to provide these requirements may be selected from the extensive thermal radiative properties tables and curves.
Standard

Spacecraft Thermal Balance

2011-07-25
CURRENT
AIR1168/12A
In the design of spacecraft, heat transfer becomes a criterion of operation to maintain structural and equipment integrity over long periods of time. The spacecraft thermal balance between cold space and solar, planetary, and equipment heat sources is the means by which the desired range of equipment and structural temperatures are obtained. With the total spacecraft balance set, subsystem and component temperatures can be analyzed for their corresponding thermal requirements. This section provides the means by which first-cut approximations of spacecraft surface, structure, and equipment temperatures may be made, using the curves of planetary and solar heat flux in conjunction with the desired coating radiative properties. Once the coating properties have been determined, the material to provide these requirements may be selected from the extensive thermal radiative properties tables and curves.
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 Equipment Environmental Control

2006-03-24
HISTORICAL
AIR1168/13
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

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

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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