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This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of APU (auxiliary power unit) engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. The baseline performance is generally determined at the original equipment manufacturer (OEM) designated test facility. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMs for the purpose of establishing certified test facilities.

This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turboprop and turboshaft engines. This Aerospace Recommended Practice (ARP) shall apply to both dynamometer and propeller based testing. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs contributed to the development of this document. Each engine manufacturer has their own practices relating to correlation and they will be used by those OEMS for the purpose of establishing certified test facilities.

The sound produced by Unmanned Aerial Systems (known as UAS or Drones) is often considered to be one of the main barriers (alongside privacy and safety concerns) preventing the widespread use of these vehicles in environments where they may be in close proximity to the general public. To better understand the potential environmental noise impact of commercial UAS operations, work undertaken by the University of Salford has focused on two key areas. Firstly, how to characterise and measure the sound produced by UAS during outdoor flight conditions and secondly, better understanding of the dose response of UAS noise when the listener is in either an indoor or outdoor environment. The paper describes a field measurement campaign undertaken to measure several UAS performing flyovers at different speeds and take-off weights.

This SAE Aerospace Recommended Practice (ARP) describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turbofan and turbojet engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. When baseline testing is performed in an indoor test cell, the baseline performance data are adjusted to open air conditions. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEM’s contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMs for the purpose of establishing certified test facilities.

This SAE Aerospace Information Report (AIR) summarizes prior empirical findings (AIAA 2018-3991; Chati, 2018) to recommend a modified baseline fuel flow rate model for jet-powered commercial aircraft during taxi operations on the airport surface that better reflects operational values. Existing standard modeling approaches are found to significantly overestimate the taxi fuel flow rate; therefore, a modified multiplicative factor is recommended to be applied to these existing approaches to make them more accurate. Results from the analysis of operational flight data are reported, which form the basis for the modeling enhancements being recommended.

As the world faces a climate crisis and ozone depletion, it is essential to turn our attention to renewable energy sources. Fossil fuels used in the automobile and aviation industry generate huge amounts of air pollution damaging the environment. Pollution generated by this industry contributes to 2.1% of all human-induced carbon dioxide emissions. Renewable energy usage has surged in the last five years to a great extent. Solar energy is one of the most widely used and available sources of energy. Solar photovoltaics accounted for 3.6% of global electricity generation, and it remains the third largest renewable electricity technology behind hydropower and wind. To generate energy through solar, solar panels are used. But the problem with solar panels is that their efficiency is low and a large number of panels are required which take up a huge amount of space on land. The area of land used for solar goes to waste.

The making of a quilt is an interesting process. Historically, a quilt is a canvas of work made from old pieces of cloth cut into squares or whatever shape that make a nice connected pattern and then stitched together. The quilt could be random pieces that is not related to each other. In most recent years and more common cases, a quilt is made of different pieces of patches that are connected and laid out in a special way to tell a story. Not only does it portray a story that is put together in a certain sequence, but it also stiches the pieces of the quilt into a nice and complete narrative. A story that one can understand just by looking at the quilt spread and unfolded. Much like the making of a quilt that has a story to tell, a Product Digital Quilt will tell the story of a product. The Digital Product Quilt replaces the conventional way of telling a product story. The traditional product story is a method that is serially connecting multiple product life cycle silos together.

This work covers the historical development of Built-In-Test (BIT) for fiber optic interconnect links for aerospace applications using Optical Time Domain Reflectometry (OTDR) equipped transceivers. The original failure modes found that installed fiber optic links must be disconnected before diagnosis could begin, often resulting in “no fault found” (NFF) designation. In fact, the observed root cause was that most (85%) of the fiber optic link defects were produced by contamination of the connector end faces. In March of 2006, a fiber optics workshop was held with roughly sixty experts from system and component manufacturers to discuss the difficulties of fiber optic test in aerospace platforms. During this meeting it was hypothesized that Optical Time Domain Reflectometry (OTDR) was feasible using an optical transceiver transmit pulse as a stimulus. The time delay and amplitude of received reflections would correlate with the position and severity of link defects, respectively.

European leaders agreed on 11 December 2020 to reduce the EU’s greenhouse gas emissions by at least 55% below 1990’s levels by 2030. Although the aviation industry accounts for about 3% of the total emissions of harmful gases produced by mankind, their concentration in the limited airspace of an airport may have an impact on the surroundings. This means that in addition to knowledge about the level of greenhouse gas (GHG) emissions, it is important to have data about the emitted amounts, propagation, and concentrations of harmful gases like CO and NOx as well as of particulate matter PM2.5 and PM10. This is particularly true over an airport, where it may afect the health of employees working directly on the apron. The airport authority should be aware of the actual amounts and concentrations of harmful emissions within the airport space, making it possible take measures leading to their reduction.

The purpose of the OBIGGS is to reduce the amount of oxygen in the fuel tank to a 'safe' level to significantly reduce the possibility of ignition of fuel vapors. There are circumstances where equipment of OBIGGS like ASMs, Ozone Converter Catalysts, etc. gets degraded earlier than the provided MTBF. This paper studies the present conventional systems limitations, like due to memory constraints only the faults and limited shop data are being recorded, hence there is no provision to store/report the stream of data margins with which we can pass/fail the performance tests. This paper also explains how a new design of the Connected concept achieves access to real-time data from the system and how the data is pushed to the cloud network.

The diesel engine is the core in the field of engineering machine power plants. While both at home and abroad for the cold start of diesel engine, the transient emission characteristics below 0 °C and above 2000m is almost a blank. Therefore, aimed at high altitude and low-temperature environment emission characteristics of cold start, this article has carried on the systematic analysis and research. In this paper, a simulation test system for the cold start of the diesel engine at low temperature at high altitude is established. The cold start experiments of a heavy diesel engine at different ambient temperatures (10°C, 0°C, -10°C and -20°C) and different altitudes (0m, 3000m, and 4000m) is carried out. In this paper, the gas emission of the diesel engine during the speed-up period of cold start is studied.

Restrictions on emissions have been made to guide society into a more sustainable development. The impasse between regulations and the expectation of a growing demand for aviation exposes the need for decarbonization of the sector. In this way, the utilization of hydrogen associated with fuel cells stands out as means to eliminate emissions during flight. This study evaluates the feasibility of using cryogenic liquid hydrogen (LH2) tanks as both energy source and cooling advantage for a small aircraft with electric propulsion. First, a propulsion system powered by a hybrid setup with Proton-Exchange Membrane Fuel Cells (PEMFC) and batteries is proposed for a small aircraft replacing an Internal Combustion Engine (ICE) and fuel tanks. Then, the new powerplant is integrated into the aircraft and simulated using the SUAVE tool.

Aviation industry currently accounts for almost 3% of worldwide greenhouse gas (GHG) emissions. Despite the continuous efforts to reduce this environmental footprint, with the use of technological efficiency driven solutions and operational changes to reduce climatic effects, such as engine improvements, fleet renewals and navigation operational improvements, the industry, which is permanently challenged by the continuously stringent standards, is aware of the need of additional measures to tackle, and even reduce, the GHG emissions, by decoupling the world's industry average growth (almost 4.1% annually) to the aviation's carbon emissions. Given its inherent operational features, the aviation sector requires fuels with high specific energy and energy density. This technical requirement makes the well known clean and efficient electrical propulsion technology to be limited to niche aviation segments (short range and low capacity airplanes) in the short and medium terms.

Begun in 2016, the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) was developed and agreed by International Civil Aviation Organization (ICAO) 191 Member States, while the Airport Carbon Accreditation was developed by the Airports, Council International Europe as a carbon management system and certification. The aviation industry has its own offsetting scheme to measure aviation emissions and carbon offsetting and it has become the first industry sector which leads the world making commitments to reduce emissions. CORSIA and the Airport Carbon Accreditation are programs that impose carbon management obligations on the aviation industry.

Ambient pressure and temperature are two main factors affecting the engine performance. As altitude increases, the air volume and air temperature entering the cylinder per cycle decrease due to the lowering of atmospheric pressure and temperature, which directly affects the engine performance. As a result, engine performance in the plateau environment degrades while the power, economy, and emission performance of the engine significantly deteriorate. This paper focuses on the simulation and parameter optimization of the combustion process of non-road methanol engines, and 1D simulation is for BSFC (Brake Specific Fuel Consumption) prediction while 3D simulation is for soot and NOx (Nitrogen Oxides) predictions. Discusses, analyzes and predicts the feasibility of non-road methanol engines for high altitude conditions. Especially the application of high proportion of methanol in non-road methanol engines at high altitudes.

Contamination from water and particulate matter in diesel or aviation fuel can cause complications even under normal operating conditions. Fuel contamination becomes a major problem in air transportation, where engine flame-out due to injection system blockage or malfunction might have catastrophic consequences. The presence of contaminants in fuel has been linked to several incidents including commercial and military aircraft over the past decade. Unless they are detected and separated from the fuel, water or solid particles have several ways to reach the engine and cause troubles. Aviation fuel is commonly stored in large tanks and transferred frequently before it reaches the aircraft, increasing the risk for contamination. At the same time, gas bubbles may be present in the system. While harmless to the aircraft, gas bubbles have been the reason why contamination monitoring systems would fail, as the system would be triggered by gas bubbles, instead of detrimental contaminants.

The more electric aircraft (MEA) concept has been attracting attention over recent decades to reduce emissions and fuel consumption. In MEAs, many subsystems that previously used hydraulic or pneumatic power have been replaced by electrical systems, and hence the weight of inverters has significant importance. The weight of inverters is largely attributed to passive filters that reduce the derivative of output voltages dv/dt and electromagnetic interference noises caused by common-mode voltages. To reduce the size of passive filters, multilevel inverters with 5 or more voltage steps are preferred. However, classic multilevel inverters have some challenges to achieve these step numbers without using plural dc power supplies that require massive transformers. In this work, a gradationally controlled voltage (GCV) inverter is proposed for MEAs.

Numerical solutions have been generated which simulate flow inside an aircraft engine flying at altitude through an ice crystal cloud. The geometry used for this study is the Honeywell Uncertified Research Engine (HURE) which was recently tested in the NASA Propulsion Systems Laboratory (PSL) in January 2018. The simulations were carried out at predicted operating points with a potential risk of ice accretion. The extent of the simulation is from upstream of the engine inlet to downstream past the strut in the core and bypass. The flow solution is produced using GlennHT, a NASA in-house code. A mixing plane approximation is used upstream and downstream of the fan. The use of the mixing plane allows for steady state solutions in the relative frame. The flow solution is then passed on to LEWICE3D for particle trajectory, impact and breakup prediction. The LEWICE3D code also uses a mixing plane approximation at the boundaries upstream and downstream of the fan.

In the present scenario, when the non-conventional energy resources are still under development stage for their full potential as a source of energy for our fast growing population, gas turbines are one of the most promising power generation technologies. The gas turbine based power utilities are also gaining acceptance across globe, because of increase in extraction of natural gas. Further reduction in the price of natural gas would also result in the number of gas turbine units installed across globe and thus it is important to carry out the environmental analysis of gas turbine based utilities. The gas turbines are employed in power generation in industries, aircrafts and marine propulsion units. The present exercise carries out thermodynamic performance analysis i.e. energy, exergy and emission performance analysis of an air-craft gas turbine. The gas turbine blades of present cycle are assumed to be cooled by air-film blade cooling technique.

In recent years, the More-Electric Aircraft (MEA) concept has undergone significant development and refinement, striving towards the attainment of reductions in noise and CO2 emissions, increased power transmission efficiency and improved reliability under a range of flight scenarios. The More-Electric Engine (MEE) is increasingly being seen as a key complementary system to the MEA. With this concept, conventional engine auxiliary systems (i.e. fuel pumps, oil pumps, actuators) will be replaced by electrically-driven equivalents, providing even greater scope for the combined aircraft and engine electrical power system optimisation and management. This concept, coupled with extraction of electrical power from multiple engine spools also has the potential to deliver significant fuel burn savings. To date, single or dual channel electrical power generation and distribution systems have been used in engines and aircrafts.