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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

AIR CONDITIONING, HELICOPTER, GENERAL REQUIREMENTS FOR

1970-10-26
HISTORICAL
ARP292B
These recommendations are written to cover the general requirements of helicopter air conditioning and are sub-divided as follows: (1) Air Conditioning System - Dealing with the general design aspects. (2) Air Conditioning Equipment - Design requirements for satisfactory system function and performance. (3) Air Conditioning System Design Requirements -General information for use of those concerned in meeting requirements contained herein.
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

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 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

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.
Standard

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.
Standard

Aerothermodynamic Test Instrumentation and Measurement

2011-07-25
CURRENT
AIR1168/5A
Like the technologies to which it contributes, the science of instrumentation seems to be expanding to unlimited proportions. In considering instrumentation techniques, primary emphasis was given in this section to the fundamentals of pressure, temperature, and flow measurement. Accent was placed on common measurement methods, such as manometers, thermocouples, and head meters, rather than on difficult and specialized techniques. Icing, humidity, velocity, and other special measurements were touched on briefly. Many of the references cited were survey articles or texts containing excellent bibliographies to assist a more detailed study where required.
Standard

Aerothermodynamic Test Instrumentation and Measurement

2006-03-27
HISTORICAL
AIR1168/5
Like the technologies to which it contributes, the science of instrumentation seems to be expanding to unlimited proportions. In considering instrumentation techniques, primary emphasis was given in this section to the fundamentals of pressure, temperature, and flow measurement. Accent was placed on common measurement methods, such as manometers, thermocouples, and head meters, rather than on difficult and specialized techniques. Icing, humidity, velocity, and other special measurements were touched on briefly. Many of the references cited were survey articles or texts containing excellent bibliographies to assist a more detailed study where required.
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

Heat Sinks for Airborne Vehicles

2021-12-15
CURRENT
AIR1957A
This document summarizes types of heat sinks and considerations in relation to the general requirements of aircraft heat sources, and it provides information to achieve efficient utilization and management of these heat sinks. In this document, a heat sink is defined as a body or substance used for removal of the heat generated by thermodynamic processes. This document provides general data about airborne heat sources, heat sinks, and modes of heat transfer. The document also discusses approaches to control the use of heat sinks and techniques for analysis and verification of heat sink management. The heat sinks are for aircraft operating at subsonic and supersonic speeds.
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.
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EQUIPMENT COOLING IN PRESENT AND IMMEDIATE FUTURE CIVIL TRANSPORT AIRCRAFT

1956-12-01
HISTORICAL
AIR64
This AIR is intended as a status report on the work of E.C.S. to date in dealing with the problem of equipment cooling in present and immediate future civil transport aircraft. Subsequent revisions to this AIR will follow as more information is gathered on this subject.
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