Browse Topic: Humidity
The purpose of air conditioning (AC) duct packing is multifaceted, serving to prevent condensation, eliminate rattle noise, and provide thermal insulation. A critical aspect of duct packing is its adhesive quality, which is essential for maintaining the longevity and effectiveness of the packing's functions. Indeed, the challenge of achieving adequate adhesivity on AC ducting parts is significant due to the harsh operating conditions to which these components are subjected. The high temperatures and presence of condensation within the AC system can severely compromise the adhesive's ability to maintain a strong bond. Moreover, the materials used for these parts, such as HDPE, often have low surface energy, which further hinders the formation of a durable adhesive bond. The failure of the adhesive under these conditions can lead to delamination of the duct packing, which can result in customer inconvenience due to rattling noises, potential electrical failures if condensed water
Moisture adsorption and compression deformation behaviors of Semimet and Non-Asbestos Organic brake pads were studied and compared for the pads cured at 120, 180 and 240 0C. The 2 types of pads were very similar in moisture adsorption behavior despite significant differences in composition. After being subjected to humidity and repeated compression to 160 bars, they all deform via the poroviscoelastoplastic mechanism, become harder to compress, and do not fully recover the original thickness after the pressure is released for 24 hours. In the case of the Semimet pads, the highest deformation occurs with the 240 °C-cure pads. In the case of the NAO pads, the highest deformation occurs with the 120 0C-cure pads. In addition, the effect of pad cure temperatures and moisture adsorption on low-speed friction was investigated. As pad properties change all the time in storage and in service because of continuously changing humidity, brake temperature and pressure, one must question any
Focused on the permanent magnet synchronous motor (PMSM) used in electric, this paper proposes an online insulation testing method based on voltage injection under high-temperature and high-humidity conditions. The effect of constant humidity and temperature on the insulation performance has been also studied. Firstly, the high-voltage insulation structure and principle of PMSM are analyzed, while an electrical insulation testing method considered constant humidity and temperature is proposed. Finally, a temperature and humidity experimental cycling test is carried out on a certain prototype PMSM, taking heat conduction and radiation models, water vapor, and partial discharge into account. The results show that the electrical insulation performance of the motor under constant humidity and temperature operation environment exhibits a decreasing trend. This study can provide theoretical and practical references for the reliable durability design of PMSM
Considerable amounts of water accumulate in aircraft fuel tanks due to condensation of vapor during flight or directly during fueling with contaminated kerosene. This can result in a misreading of the fuel meters. In certain aircraft types, ice blocks resulting from the low temperatures at high altitude flights or in winter time can even interfere with the nozzles of the fuel supply pipes from the tanks to the engines. Therefore, as part of the maintenance operations, water has to be drained in certain intervals ensuring that no remaining ice is present. In the absence of an established method for determining residual ice blocks inside, the aircraft operator has to wait long enough, in some cases too long, to start the draining procedure, leading potentially to an unnecessary long ground time. A promising technology to determine melting ice uses acoustic signals generated and emitted during ice melting. With acoustic emissions, mainly situated in the ultrasonic frequency range, a very
In the last decades there have been many temporary engine failures, engine-related events and erroneous airspeed indication measurements that occurred by a phenomenon known as Ice Crystal Icing (ICI). This type of icing mainly occurs in high altitudes close to tropical convection in areas with a high concentration of ice crystals. Direct measurements or in-situ pilot observations of ICI that could be used as a warning to other air-traffic are rare to nearly non-existent. To detect those dangerous high Ice Water Content (IWC) areas with already existing airborne measurement instruments, Lufthansa analyzed observed Total Air Temperature (TAT) anomalies and used a self-developed search algorithm, depicting those TAT anomalies that are related to ice crystal icing events. To optimize the flight route for dispatchers several hours before the flight, e.g. for long distance flights through the intertropical convergence zone (ITCZ), reliable forecasts to identify hazardous high IWC regions are
These methods of test are applicable for determining the resistance to snagging and abrasion of automotive bodycloth, vinyl, and leather
This specification describes a method and acceptance criteria for testing automotive wire harness retainer clips. Retainer clips are plastic parts that hold a wire harness or electrical connector in a specific position. Typical plastic retainers work by having a set of “branches” that can be inserted into a hole sized to be easy to install but provide acceptable retention. This specification tests retainer clips for mechanical retention when exposed to the mechanical and environmental stresses typically found in automotive applications over a 15-year service life. This specification has several test options to allow the test to match to the expected service conditions. The variability of applications typically arises from different ambient temperatures near the clip, different proximity to automotive fluids, different exposure to standing water or water spray, and different thicknesses of the holes that the clip is inserted into. Clips are typically inserted into sheet or rolled metal
This procedure establishes a recommended practice for performing a lumbar flexion test to the Hybrid III 50th male anthropomorphic test device (ATD or crash dummy). This test was created to satisfy the demand from industry to have a certification test which characterizes the lumbar without interaction of other dummy components. In the past, there have not been any tests to evaluate the performance of Hybrid III 50th lumbar
This method is used to define the immunity of electric and electronic apparatus and equipment (products) to radiated electromagnetic (EM) energy. This method is based on injecting the calibrated radio frequency currents (voltages) into external conductors and/or internal circuits of the product under test, measuring the strength of the EM field generated by this product and evaluating its immunity to the external EM field on the basis of the data obtained. The method can be utilized only when it is physically possible to connect the injector to the conductors and/or circuits mentioned before. The method allows: Evaluating immunity of the product under test to external EM fields of the strength equal to a normalized one; Calculating the level of external EM field strength at which the given (including maximum permissible) induced currents or voltages are generated in the equipment under test, or solving the “opposite” task; Finding potentially “weak” points of the product design
A typical modern automobile compressor-driven air conditioner, about powerful enough to cool a house, may not be needed even in very hot, humid climates if we combine insights from comfort theory with innovations in comfort delivery, photonics, and superefficient thermal and air-handling devices. Recent advances can successively minimize unwanted heat gain into the passenger cabin, cool people’s bodies rather than the vehicle, deliver highly effective radiant cooling, passively reject extracted heat to the sky, and, if needed, move air very efficiently and quietly to expand the human comfort range. Together these proven innovations may give automotive occupants excellent hot-weather comfort without refrigerative air conditioning. This substitution could improve climate protection and electric-vehicle range, cut the automobile’s weight and cost, avoid climate and ozone harm from refrigerants, reduce noise and air pollution, make autos more energy-efficient, and save the United States
This SAE Aerospace Recommended Practice (ARP) covers the requirements for a Stationary Runway Weather Information System (referred to as the system) to monitor the surface conditions of airfield operational areas to ensure safer ground operations of aircraft. The system provides (1) temperature and condition information of runway, taxiway, and ramp pavements and (2) atmospheric weather conditions that assist airport personnel to maintain safer and more efficient airport operations. The system can be either a wired system or a wireless system
This SAE Aerospace Recommended Practice (ARP) covers the requirements for a combined Mobile Digital Infrared Pavement Surface, Ambient Air, and Dew Point Temperature Sensing System (referred to as the system). The system monitors real-time surface, air and dew point temperatures of airfield pavement areas to ensure safe winter ground operations of aircraft and other vehicles. The vehicle mounted electronic system provides the operator with real-time readings of surface, air and dew point temperatures of airfield pavement areas including runways, taxiways, ramps, bridges, vehicular roadways, parking garages and parking lots. The electronic system shall be available with or without the dew point sensing option. This electronic system can be utilized as a stand alone system at small airports, or may be used to augment airport operations that currently have a Stationary Runway Weather Information System (reference ARP5533). Because the electronic system is mobile, it can be utilized to
This test is designed to measure the thickness of textiles, plastics, and similar materials
This SAE Aerospace Standard (AS) establishes the surface pretreatment, temperature, and baking time required to cure AS5272 lubricant when it is applied over the surfaces of manufactured parts of various metals
This specification covers a resin-impregnated glass fabric honeycomb core in the form of flat or contoured sandwich structures
This specification covers an aluminum alloy in the form of plate from 3.000 to 8.000 inches (76.20 to 203.20 mm) in thickness (see 8.5
This specification covers the requirements for adhesives in film form for bonding metal facings to metal cores and to metal components of sandwich panels which are intended for use in primary and secondary structural airframe parts that may be exposed to temperatures up to 500°F (260°C
This specification and its supplementary detail specifications cover organic fibers in the form of cloth impregnated with epoxy resin, the resin to be supplied in a "B" stage condition
The kinetics of moisture adsorption is studied for copper-free brake pads. The pad weight gain is found to increase linearly with the square root of exposure time to humidity at a given temperature in the initial stage of adsorption - the higher the humidity, the higher the weight gain. Pads cured at 150°C adsorb less moisture than pads cured at 220°C. As the moisture content in the pad increases, the tangent modulus increases while the secant modulus decreases, resulting in decreasing compressibility associated with the tangent modulus of compression and increasing compressibility associated with the secant modulus of compression - compressibility defined as a reciprocal of compression modulus. Static modulus of compression, dynamic modulus of compression and hardness measurements are compared, and they all show the same trend. A rate constant of adsorption is proposed to define and compare moisture sensitivity of friction material
This procedure is used to determine seam strength and seam fatigue of automotive textiles, vinyl coated fabrics and related soft trim materials
This method of test applies to the measurement of elastic and recovery properties of materials after being subjected to a low-static load
This test method covers determination of abrasion resistance, fiber loss, and bearding resistance of automotive carpet materials
This specification covers a foaming-type, heat-curing, resin-base adhesive in the form of paste or sheet
This specification covers a corrosion-inhibiting, water soluble, modified epoxy primer in liquid form
This specification covers the requirements for nonperforated nylon paper base plastic honeycomb core material for aircraft structural applications, including exterior parts such as radio and radar antenna housings
This specification covers a foaming-type, heat-curing, resin-base adhesive in the form of paste or sheet
This SAE Standard presents a method of determining the stiffness of interior trim materials, substrates, and composites by a three-point bending test
This SAE Aerospace Standard (AS) covers the following basic types: Type I - Pitot pressure, straight and L-shaped, electrically heated. Type II - Pitot and static pressures, straight and L-shaped, electrically heated
This SAE Aerospace Standard (AS) specifies minimum performance requirements for pressure altimeter systems other than air data computers. This document covers altimeter systems that measure and display altitude as a function of atmospheric pressure. The pressure transducer may be contained within the instrument display case or located remotely. Requirements for air data computers are specified in AS8002. Some requirements for nontransducing servoed altitude indicators are included in AS791. This document does not address RVSM requirements because general RVSM requirements cannot be independently detailed at the component level. The instrument system specified herein does not include aircraft pressure lines. Unless otherwise specified, whenever the term “instrument” is used, it is to be understood to be the complete system of pressure transducer components, any auxiliary equipment, and display components. The test procedures specified herein apply specifically to mechanical type
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