Browse Topic: Air supply
This SAE Aerospace Recommended Practice (ARP) contains guidelines and recommendations for subsonic airplane air conditioning systems and components, including requirements, design philosophy, testing, and ambient conditions. The airplane air conditioning system comprises that arrangement of equipment, controls, and indicators that supply and distribute air to the occupied compartments for ventilation, pressurization, and temperature and moisture control. The principal features of the system are: a A supply of outside air with independent control valve(s). b A means for heating. c A means for cooling (air or vapor cycle units and heat exchangers). d A means for removing excess moisture from the air supply. e A ventilation subsystem. f A temperature control subsystem. g A pressure control subsystem. Other system components for treating cabin air, such as filtration and humidification, are included, as are the ancillary functions of equipment cooling and cargo compartment conditioning
This Aerospace Information Report (AIR) outlines the design considerations and criteria for the control of water carryover from the environmental control system (ECS) with respect to causes and indicated corrective or preventative action. In addition, condensation on structure will be reviewed with possible preventative action described
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
The intention of this standard is to establish a framework to measure the efficiency of PWM HVAC Blower Controllers and Brushless DC Motor Controllers and define a usage based overall efficiency. This result can then be used by vehicle OEMs to demonstrate compliance towards requirements or benchmarks established by regulatory agencies
Air Supply Unit (ASU) serves as the pneumatic source for the air suspension system in the passenger car segment. The ASU is an electrically driven oil-free compressor with integrated air dryer to deliver dry air to the suspension system. Solenoid valve, Height Sensor and ECU adjusts the pressure in bellow based on the vehicle load condition. During the lab test, pressure was not building up in the compressor due to delivery valve failure. The type of valve in asu is reed valve type, it is mostly used in the micro compressors due to its low cost, simple structure and light weight configuration. The reed movement is based on the pressure difference between the inlet and the compression chamber. Failure analysis is carried out based on the finite element analysis to identify the root cause, the root cause identified is optimized to prevent the failure. An accelerated test condition is arrived based on the FEA and a tailored series of accelerated tests are carried out to reproduce the
Proton exchange membrane fuel cells (PEMFC) are considered an environment-friendly alternative vehicle power in the future owing to their high power density and zero-carbon emission. To research the performance of the air supplied by the PEMFC air system, the PEMFC air system bench composed of an air compressor, cooler, emulated stack, back-pressure valve, and sensors was built. Then, a PEMFC system test bench composed of a hydrogen supply subsystem, stack, air supply subsystem, electronic control subsystem, and cooling subsystem was established. The fuel cell system control parameters and control method are complex due to the coupling and nonlinearity of the air supply system. The strategy composed of a feedforward table and piecewise proportional integral (PI) feedback control strategy was employed to regulate the pressure and flow rate of the air supply system. The air compressor map and the mapping relationship among the air compressor speed, opening of the back-pressure valve, and
This SAE Recommended Practice provides instructions and test procedures for air braked vehicles including but not limited to trucks, truck-tractors, trailers, dollies, and buses used on highways but does not include off-highway vehicles
This SAE Aerospace Recommended Practice (ARP) applies to blankets used for passenger comfort within transport category aircraft cabins. When the term “blanket” is used in this document it refers to all blankets that are provided by the aircraft operator for passenger warmth
The existing compressor plants at railroad marshalling yards (MYs) are equipped with automatic compressed air supply control systems. However, this is implemented using outdated and ineffective methods. Taking into account the current trends in the field of three-phase motor control, as well as the requirements for energy saving, the most effective is the frequency regulation of performance. The work provides a justification for the need to use a variable frequency drive of a compressor unit (CU). A mathematical model has been developed for controlling an asynchronous motor (AM), taking into account the setting coefficient of performance. As a result, a computer simulation model for controlling the drive motor of a reciprocating compressor at an MY has been proposed and tested. The diagrams and values obtained made it possible to study in detail the automatic control system of the drive and select the optimal control laws for the frequency-controlled unit. An analysis of the results of
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
An airplane fuel tank inerting system provides an inert atmosphere in a fuel tank to minimize explosive ignition of fuel vapor. This SAE Aerospace Information Report (AIR) deals with the three methods of fuel tank inerting systems currently used in operational aircraft: (1) on-board inert gas generation systems (OBIGGS), (2) liquid/gaseous nitrogen systems, and (3) halon systems. The OBIGGS and nitrogen systems generally are designed to provide full-time fuel tank fire protection; the halon systems generally are designed to provide only on-demand or combat-specific protection. This document also addresses other design considerations that affect fuel tank flammability such as fuel tank pressure and other methods for reducing fuel tank flammability. This AIR does not treat the subject of explosion suppression foam (ESF) that has been used for fuel tank explosion protection on some military aircraft. ESF is also available for retrofit for commercial airplanes. The primary disadvantages of
The article proves the necessity for heating the air in the pneumatic engine of a hybrid power unit designed for moving a compact wheeled vehicle. The aim is to improve the pneumatic engine operation indicators by heating the compressed air before it is supplied to the cylinder using the obtained theoretical and experimental studies. For the easy-to-use of assessing the effectiveness of heating the air supplied to a pneumatic engine, the experiments were carried out by two pressure ps = 0.7 MPa and ps = 0.9 MPa, according to them the testing of a pneumatic unit was conducted without heating the compressed air at the temperature equal to the ambient temperature Ts = 293 K. Also, during the experiments a pneumatic engine was tested at other temperatures while supplying the compressed air at the inlet to the engine cylinder. So, at an inlet pressure ps = 0.7 MPa, the compressed air was heated up to the temperature Ts = 383 K, and at a pressure ps = 0.9 MPa it was heated up to the
This document considers the cooling of equipment installed in equipment centers, which usually consist of rack-mounted equipment and panel mounted equipment in the flight deck. Instances where these two locations result in different requirements are identified. This document generally refers to the cooled equipment as E/E equipment, denoting that both electrical and electronic equipment is considered, or as an E/E equipment line-replaceable-unit (LRU). The majority of cooled equipment takes the form of LRUs. The primary focus of this document is E/E equipment which uses forced air cooling to keep the equipment within acceptable environmental limits. These limits ensure the equipment operates reliably and within acceptable tolerances. Cooling may be supplied internally or externally to the E/E equipment case. Some E/E equipment is cooled solely by natural convection, conduction, and radiation to the surrounding environment. This document discusses specification requirements, system
In Toyota’s 2nd generation FCV, an electric turbo-type air compressor has been adopted for downsizing and cost reduction. Automotive Fuel Cell applications present several challenges for implementing a turbo-type air compressor. When operating a fuel cell in high-temperature or high-altitude locations, the FC stack must be pressurized to prevent dry-up. The flow rate vs pressure conditions that the FC must pass through or in some cases operate at are typically within the surge region of a turbo-type air compressor. Additionally, Toyota requires quick air transient response (< 1 sec) for power generation, energy management, and FC dry-up prevention. If the turbo-type air compressor is not precisely controlled during quick transients, it can easily enter the surge region. To solve the above issues, we developed a new air supply controller which can avoid compressor surge by controlling 3 variables, ‘FC stack air flowrate’, ‘FC stack air pressure’, and ‘FC stack air Bypass’ independently
This SAE recommended practice provides procedures and methods for testing service, spring applied parking and combination brake actuators for air disc brake applications. Methods and recommended samples for testing durability, function and environmental performance are listed in 1.1 and 1.2
Mechanical friction and heat transfer in internal combustion engines are two highly researched topics, due to their importance on the mechanical and thermal efficiencies of the engine. Despite the research efforts that were done throughout the years on both these subjects, engine modeling is still somewhat limited by the use of sub-models which do not fully represent the phenomena happening in the engine. Developing new models require experimental data which is accurate, repeatable and which covers wide range of operation. In SAE 2018-01-0121, the conventional pressurized motored method was investigated and compared with other friction determination methods. The pressurized motored method proved to offer a good intermediate between the conventional motored tests, which offer good repeatability, and the fired tests which provide the real operating conditions, but lacks repeatability and accuracy. A ‘shunt pipe’ was utilized between the intake and exhaust manifolds which reduced
This SAE Aerospace Information Report (AIR) includes a discussion of liquid and particulate contaminants which enter the aircraft through the environmental control system (ECS). Gaseous contaminants such as ozone, fuel vapors, sulphates, etc. are also covered in this AIR. This publication is concerned with contamination sources which interface with ECS and fuel tank inerting systems, and the effects of this contamination on equipment. Methods of control will be limited to the equipment and interfacing ducting which normally falls within the responsibility of the ECS designer
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
This SAE Aerospace Recommended Practice (ARP) discusses design philosophy, system and equipment requirements, environmental conditions, and design considerations for rotorcraft environmental control systems (ECS). The rotorcraft ECS comprises that arrangement of equipment, controls, and indicators which supply and distribute dehumidified conditioned air for ventilation, cooling and heating of the occupied compartments, and cooling of the avionics. The principal features of the system are: a A controlled fresh air supply b A means for cooling (air or vapor cycle units and heat exchangers) c A means for removing excess moisture from the air supply d A means for heating e A temperature control system f A conditioned air distribution system The ARP is applicable to both civil and military rotorcraft where an ECS is specified; however, certain requirements peculiar to military applications—such as nuclear, biological, and chemical (NBC) protection—are not covered. The integration of NBC
Continuous efforts to improve thermal efficiency and reduce exhaust emissions of internal combustion engines have resulted in development of various solutions towards improved lean burn ignition systems in spark ignition engines. The Dual Mode, Turbulent Jet Ignition (DM-TJI) system is one of the leading technologies in that regard which offers higher thermal efficiency and reduced NOx emissions due to its ability to operate with very lean or highly dilute mixtures. Compared to other pre-chamber ignition technologies, the DM-TJI system has the distinct capability to work with a very high level of EGR dilution (up to ~40%). Thus, this system enables the use of a three-way catalyst (TWC). Auxiliary air supply for pre-chamber purge allows this system to work with such high EGR dilution rate. This work presents the results of experimental investigation carried out with a Dual Mode, Turbulent Jet Ignition (DM-TJI) optical engine equipped with a cooled EGR system. The results show that the
Fuel cell technology can play a major role in reducing transportation-related emissions, especially in heavy-duty, long-haul applications. Consequent transfer of technology from air supply systems for combustion engines to cathode air paths serves as an enabler for necessary system cost reduction. To achieve the required system lifetime, the supply of clean air is essential. Gases like NOx, SO2 and NH3 poison the catalyst, leading to increased stack degradation rates. Effective removal with functionalized activated carbons enhances the catalyst´s lifetime. Research on real-life concentrations of these contaminants under different driving patterns and road profiles enables knowledge-based design of cathode air filter elements. To prevent flooding of components like air filter, humidifier, or stack, water separators are integrated at different position inside the system. Plastic air ducts with integrated sensors and flaps required to manage the air flow connect the different functional
A tested method of data presentation and use is described herein. The method shown is a useful guide, to be used with care and to be improved with use
This SAE Recommended Practice provides instructions and test procedures for measuring air consumption of air braked vehicles equipped with Antilock Brake Systems (ABS) used on highways
The dynamic and efficiency of automotive fuel cell drives is significantly influenced by air supply system. Different air compression architectures use electric compressor (EC), electric turbocharger (ETC), or a serial booster (SB) consisting of turbocharger and electric compressor. These three variants of air compression systems were modeled using a map approach and added to a 0D fuel cell air supply model. The characteristic maps of the turbomachinery were measured on the test bench under fuel cell conditions. Subsequently, the calculated isentropic efficiencies were corrected with respect to heat transfer phenomena occurring during the measurement. Moreover, a scaling method for the maps of the turbomachinery is explained. The initial simulation of the air compression systems with equal diameters for the turbomachinery showed no difference in the mechanical power demand. Therefore, the particle swarm algorithm (PSA) was applied to optimize the turbomachinery maps of EC, ETC, and SB
This SAE Recommended Practice provides procedures and methods for testing service, spring applied parking, and combination brake actuators with respect to durability, function, and environmental performance. A minimum of six test units designated A, B, C, D, E, and F are to be used to perform all tests per 1.1 and 1.2
This SAE Aerospace Recommended Practice (ARP) contains guidelines and recommendations for subsonic airplane air conditioning systems and components, including requirements, design philosophy, testing and ambient conditions. The airplane air conditioning system comprises that arrangement of equipment, controls and indicators that supply and distribute air to the occupied compartments for ventilation, pressurization, and temperature and moisture control. The principal features of the system are: a A supply of outside air with independent control valve(s). b A means for heating c A means for cooling (air or vapor cycle units and heat exchangers) d A means for removing excess moisture from the air supply e A ventilation subsystem f A temperature control subsystem g A pressure control subsystem Other system components for treating cabin air such as filtration and humidification are included, as are the ancillary functions of equipment cooling and cargo compartment conditioning. The
High pressure fuel cell engine, namely high pressure fuel cell system for automobiles, is the core power plant of fuel cell vehicle. Among many categories of fuel cells, proton exchange membrane fuel cell (PEMFC) is the most widely used one for automotive applications, with the characteristic of high power density, fast response and moderate working conditions. The cathode oxygen supply in PEMFC is one of the most important factors which affects its output power and operational lifespan. Reasonable regulation of air supply process flow and pressure can effectively improve system’s performance and efficiency. In this paper, a mathematical model of the air supply system and a model of altitude and environmental pressure are established in MATLAB \ Simulink by mechanism modeling method. Then the modules of the air supply system are integrated to supply air to the 85 KW PEMFC stack model. According to the nonlinear optimal theory, the optimal steady-state condition of the system under
Several methods are nowadays used by OEM’s in order to determine engine friction through experiments to help them develop friction correlations to be used in 1D simulation models. Some of the friction measurement methods used are; Willans Line, Morse test, Teardown test and Indicated Method. Each of these methods have their own disadvantages, with some reliant on heavy assumptions. In this paper a friction measurement method is discussed which requires a conventional motoring dynamometer cell by which the engine can be motored at different speeds. The exhaust manifold of the motored 2 litre, 4 cylinder diesel engine was shorted to the intake manifold with an unrestrictive ‘shunt’ pipe which reroutes the exhausted air to the intake [1]. The shunt pipe was pressurized by an external source of compressed air to make up for blow-by losses. It is noted that the compressed air supply is thus a small fraction of what would be required if no recirculation is used. In fact a small compressor
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