Abstract While the design of nozzles for diatomic gases is very well established and covered by published works, the case of a diatomic gas dissociating to monatomic along a nozzle is a novel subject that needs a proper mathematical description. These novel studies are relevant to the definition of nozzles for gas-core Nuclear Thermal Rockets (NTR) that are receiving increased attention for the potential advantages they may deliver versus current generation rockets. The article thus reviews the design of the nozzles of gas-core NTR that use hydrogen as the propellant. Propellant temperatures are expected to reach 9,000-15,000 K. Above 1500 K, hydrogen begins to dissociate at low pressures, and around 3000 K dissociation also occurs at high pressures. At a given temperature, the lower the gas pressure the more molecules dissociate, and H2 → H + H. The properties of the gas are a function of the mass fractions of diatomic and monatomic hydrogen x H2 and x H = 1 − x H2.
Abstract The paper presents a complete description of the design and manufacturing of a Carbon Fiber/epoxy mold with an embedded Carbon Fiber resistor heater, and the mold performances in terms of its surface temperature distribution and thermal deformations resulting from the heating. The mold was designed for manufacturing aileron skins from Vacuum Bag Only prepreg cured at 135°C. The glass transition temperature of the used resin-hardener system was about 175°C. To ensure homogenous temperature of the mold working surface in the course of curing, the Carbon Fiber heater was embedded in a layer of a highly heat-conductive cristobalite/epoxy composite, forming the core of the mold shell. Because the cristobalite/epoxy composite displayed much higher thermal expansion than CF/epoxy did, thermal stresses could arise due to this discrepancy in the course of heating.
This document outlines the current state of the art in the understanding of gas in solution in shock absorber oils in unseperated shock absorbers. A literature review, overview of Henry's law, Henry's law coefficients for known gas and oil couples, in-service operational problems, lessons learned, and potential future work will be discussed in the document.
This document outlines historical systems which have used the landing gear as a sensor or installation point for full aircraft weight and balance systems. A number of systems have been developed, installed, certified, and placed in service but few systems remain in regular use. The document will capture the history of these systems, reasons (where known) for their withdrawal from service, and lessons learned.
This document will outline existing best practices in the instrumentation of landing gears for in-service operation (including flight test, operational loads monitoring, etc.).
This report will document Runway Condition Monitoring systems that provide information intended to reduce or eliminate aircraft runway excursions or overruns that may occur as a result of poor runway conditions.
This document describes the approaches taken to define safe-life limits for the management of fatigue in landing gear structures, and the substantiation of those limits through full-scale fatigue testing. The safe-life scatter factors considered in a range of military and civil regulatory standards are also reviewed.
The scope of the test method is to provide stakeholders including fluid manufacturers, brake manufacturers, aircraft constructors, aircraft operators and airworthiness authorities with a relative assessment of the effect of deicing chemicals on carbon oxidation. This test is designed to assess the relative effects of runway deicing chemicals by measuring mass change of contaminated and bare carbon samples tested under the same conditions.
This document was requested by the FAA to provide a technical update of TSO-C26d to address Electric Brake Actuation, standardize with TSO-C135a and address any remaining concerns with the current technical requirements in AIR5381.
This SAE Aerospace Standard (AS) prescribes the Minimum Performance Standards (MPS) for environmental conditions that wheel, brake, and wheel and brake assemblies to be used on aircraft certificated under 14 CFR Parts 23, 25, 27, and 29. The environmental requirements in this document shall be used in conjunction with other MPS defined in Technical Standard Orders for the applicable equipment.
This document will compile and harmonize the performance requirements of elastomeric seals in potable water systems. Suppliers who have certifications equivalent to NSF 61 can qualify to produce both the ethylene propylene rubber compound and O-rings.
The document provides a definition of skew and disconnect occuring in high lift systems in flight controls including their hazard assessment, describes generic solutions and provides a for specifying requirements.
Scope: This Aerospace Recommended Practice (ARP) provides guidelines for specifying dielectric withstanding strength and insulation resistance design and test requirements for aircraft line replaceable units (LRU's) used within a flight control and/or a utility system. 1.1 Purpose The testing is intended to verify that an LRU can operate safely at its rated voltage and withstand momentary over potentials due to switching, troubleshooting testing, surges, etc.. The testing is also intended to verify adequate design margin of the insulation system and detect workmanship problems.
This document provides recommendations for obtaining a finish and texture for reciprocating sealing surfaces in fluid power systems to improve dynamic seal performance. Recommendations on how to specify and measure the surface finish are also provided.
This SAE Aerospace Recommended Practice (ARP) is intended as a guide to define the requirements for aerospace hydraulic shuttle valves, including details pertinent to the design, performance, fabrication, and testing of the shuttle valves.
This Aerospace Recommended Practice (ARP) offers guidelines for specifying servoloop pressure feedback transducers for use in hydraulic actuation for servosystems.