Browse Topic: Pressure
This SAE Aerospace Recommended Practice (ARP) describes a method of conducting an endurance test using contaminated air when the applicable specification requires non-recirculation of the contaminants. The objective of the test is to determine the resistance of the engine mounted components to wear or damage caused by the contaminated air. The method described herein calls for non-recirculation of the contaminants and is intended to provide a uniform distribution of the contaminant at the inlet to the Unit Under Test (UUT). The UUT may require the use of a hydraulic fluid for actuation of components within the test unit. Contamination of the test hydraulic fluid is not part of this recommended practice. If contaminated hydraulic fluid is required by the applicable test specification, refer to MAP749
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
This SAE Aerospace Standard (AS) defines the requirements for air cycle air conditioning systems used on military air vehicles for cooling, heating, ventilation, and moisture and contamination control. General recommendations for an air conditioning system, which may include an air cycle system as a cooling source, are included in MIL-E-18927E and JSSG-2009. Air cycle air conditioning systems include those components which condition high temperature and high pressure air for delivery to occupied and equipment compartments and to electrical and electronic equipment. This document is applicable to open and closed loop air cycle systems. Definitions are contained in Section 5 of this document
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
The automotive industry faces unprecedented regulatory and societal pressure to adopt sustainable manufacturing practices. A recent survey by Accenture shows that more than 34 percent of today’s largest manufacturers have committed to zero-emission goals, yet 93 percent of them will miss their targets unless they double their emission reduction rates by 2030
A new groundbreaking “smart glove” is capable of tracking the hand and finger movements of stroke victims during rehabilitation exercises. The glove incorporates a sophisticated network of highly sensitive sensor yarns and pressure sensors that are woven into a comfortable stretchy fabric, enabling it to track, capture, and wirelessly transmit even the smallest hand and finger movements
Sustainability remains a dominant trend in packaging and processing, continuing to attract the attention of the life sciences industry and inspire its new initiatives. Although pharmaceutical and medical device manufacturers must prioritize patient safety and product protection, concerns about climate change, greenhouse gas (GHG) emissions, plastic waste, and pressure to move toward a circular economy are prompting a greater focus on improving the sustainability of their products and packaging
Continental's Georg Fässler, executive chair of the 2024 SAE COMVEC, details efforts to future-proof forthcoming vehicles. Severe driver shortages, rising fuel and material costs, escalating demand for freight transport, higher sustainability requirements - there is no shortage of challenges facing the transport sector. Commercial vehicle manufacturers and industry suppliers are devoting significant resources to develop, test and bring to market the technological advances that will help alleviate these pressure points. “The digitalization of commercial vehicles and the whole logistics chain is a necessary response and one of the most important developments in the CV industry in my view,” said Continental Automotive's head of commercial and special vehicles, Georg Fässler, in a recent interview with SAE International
Tank Technologies, a company producing porcelain-lined water heaters, faced significant challenges with their manual cutting processes. Challenges in the cutting process are detrimental in an industrial landscape where speed requirements and cost pressures are high. The introduction of Hirebotics’ Cobot Cutter significantly improved their operations, drastically reducing rework, improving cycle times, and elevating overall efficiency
If an external force with changing amplitude acts on an elastic medium such as a gas, a liquid or a solid, an undulating propagation of pressure and density fluctuation occurs in space and time, starting from the point where the force is applied. This is known as sound. The frequency of sound waves ranges from a few hertz (Hz) up to several gigahertz (see Figure 1). Infrasound, the sound humans cannot hear, lies at frequencies below 16 Hz. It is followed by the hearing range, which reaches up to 20 kHz. Ultrasonic waves, which cannot be heard, lie in the frequency range from 20 kHz to 1.6 GHz, which equals 16 billion cycles per second. A prominent application example in medical technology is the use of ultrasound for diagnostic imaging techniques. In industry and research, ultrasound is mainly used in measurement technology, where sound waves with low power are used. The intensity of the sound describes the power that hits a certain surface. If it exceeds 10 W/cm2, we speak of power
Membranes of vertically aligned carbon nanotubes (VaCNT) can be used to clean or desalinate water at high flow rate and low pressure. Recently, researchers of Karlsruhe Institute of Technology (KIT) and partners carried out steroid hormone adsorption experiments to study the interplay of forces in the small pores. They found that VaCNT of specific pore geometry and pore surface structure are suited for use as highly selective membranes. The research was published in Nature Communications
This study aims to design a supersonic ejector, referred to as a liquid spray gun, with a simple operating procedure for producing an aerosol spray with adjustable droplet size distributions. A CFD model was developed to determine the influence of nozzle exit position and the primary air pressure on the supersonic patterns formed within the ejectors, providing a valuable insight into their internal physics. Based on the single-phase numerical results, at an air primary pressure of 2 bar, the flow may not reach a choking condition, possibly resulting in unstable ejector operation. However, at pressures exceeding 5 bar, the jet patterns emerging from the primary nozzle cause flow separation or the formation of vortex rings. This phenomenon leads to a flow configuration comparable to the diameter of the mixing tube, thereby reducing the available area for entrainment of suction flow. The suitable ejector was identified with a nozzle exit position of 13 mm and a primary pressure ranging
Recent advances in technology have opened many possibilities for using wearable and implantable sensors to monitor various indicators of patient health. Wearable pressure sensors are designed to respond to very small changes in bodily pressure, so that physical functions such as pulse rate, blood pressure, breathing rates, and even subtle changes in vocal cord vibrations can be monitored in real time with a high degree of sensitivity
Thin cylindrical shells under compressive loads typically experience failure through buckling. The buckling phenomenon in these structures often demonstrates a notable disparity between theoretical predictions and experimental outcomes. In the design of such structures, the theoretically determined critical load undergoes a reduction through a factor known as the Buckling Knockdown Factor (KDF). Traditionally, KDF has been empirically derived, and conservative lower bounds are established in industry standards. Recognizing the importance of minimizing structural mass, recent literature has presented promising results for estimating KDF using numerical methods in the context of cylinders under axial compression. This paper addresses the novel challenge of estimating KDF for cylinders subjected to external pressure using numerical techniques. A comprehensive survey of various methods for KDF estimation is conducted, and the Single Perturbation Load Analysis (SPLA) method, a deterministic
In commercial aerospace, the application areas for motors are wide and varied, each with their own unique requirements. From electric vehicle take-off and landing (eVTOL) air taxis to business jets to long-haul commercial transport aircraft, DC motors must endure various environmental conditions like extreme temperatures, shock and vibration, atmospheric pressures and signal interference, to name just a few. These applications may also demand motors that provide a fast response, high power or torque density. In addition to these requirements, the aerospace industry perpetually calls for lightweight materials and smaller installation spaces. Taken together, it can be very difficult to specify and buy a reliable motor for mission-critical equipment. This article will present common commercial aerospace applications that pose performance and environmental challenges for DC motors along with a summary of the stringent aerospace industry standards that the motors must satisfy. It will also
Researchers at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Columbia University have developed a way to convert carbon dioxide (CO2), a potent greenhouse gas, into carbon nanofibers, materials with a wide range of unique properties and many potential long-term uses. Their strategy uses tandem electrochemical and thermochemical reactions run at relatively low temperatures and ambient pressure. As the scientists describe in the journal Nature Catalysis, this approach could successfully lock carbon away in a useful solid form to offset or even achieve negative carbon emissions
The bi-stable phenomena of the Ahmed model were experimentally studied at different rear slant angles (31.8 °, 42 °, 50 °, 60 °, 75 °, 90°) and different Reynolds numbers (9.2 × 104, 1.84 × 105, 2.76 × 105). The analysis of pressure gradients both on the base and slant indicate that no bi-stable phenomena were observed at different Reynolds numbers when the slant angle was less than or equal to 50°. However, for the rear slant angles greater than or equal to 60°, the pressure gradients consistently shift between two preferred values at various Reynolds numbers, indicating the presence of bi-stable behavior in the spanwise direction. Therefore, the critical angle for the appearance of bi-stability in the Ahmed model lies within the range of 50° to 60°, and the existence of bistable behavior remains unaffected by the Reynolds number. As the slant angle increases, the switching rate decreases significantly until the angle is greater than 60°. Furthermore, with an increase in Reynolds
Usually developing slowly over time, many cases of glaucoma are only picked up during routine eye tests, by which time lasting damage may already have been caused. But this could change in the future as academics from the U.K. and Türkiye have developed a contact lens which can detect changes in eye pressure which signal possible glaucoma
Researchers have developed a biomimetic scaffold that generates electrical signals upon the application of pressure by utilizing the unique osteogenic ability of hydroxyapatite (HAp). HAp is a basic calcium phosphate material found in bones and teeth
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