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The search for ever-lower emission technology for future generations of aircraft engines is actively progressing on both sides of the Atlantic. Tucked away on a modest-size stand at this year’s Farnborough International Airshow was a highly varied collection of unconventional engine technology displays – a clear indication of radical innovation already being investigated as a part of Ultimate, the European Horizon 2020 research and innovation project.

In part two of a two-part series, Richard Gardner discusses various aerospace propulsion innovations and continued work by aerospace engineers and scientists to advance aircraft engine technologies to increase efficiency and lower emissions.

Aircraft potable (drinking) water systems haven’t changed significantly in the last half-century. These systems consist of cylindrical water tanks pressurized by bleed air from the jet engines, with insulated stainless steel distribution lines. What has changed recently is the increase in the possibility of aircraft picking up contaminated drinking water at foreign and domestic stops. Customer awareness of these problems has also changed - to the point where having reliable drinking water is now a competitive issue among airlines. Old style potable water systems that are used on modern aircraft are high maintenance and exacerbate the growth of microbes because the water is static much of the time. The integrity of some pressurized water tanks are also a concern after years of use. Cost-effective mechanical and biological solutions exist that can significantly reduce the amount of chemicals added and provide good potable water.

A helicopter blade profile was tested in the DGA Aero-engine Testing's icing altitude test facility S1 in Saclay, France during the winter of 2013/2014. The airfoil was a helicopter main rotor OA312 blade profile made out of composite material and with a metallic erosion shield. Dry air and ice accretion tests have been performed in order to assess the iced airfoil's aerodynamic behaviour. Several icing conditions were tested up through Mach numbers around 0.6. This paper presents the test setup, the test model and some of the test results. The test results presented in this paper include the ice shapes generated as well as dry air and iced airfoil lift and drag curves (polars) which were obtained with the real ice shapes on the airfoil.

The characteristics of turbines for turbojet and space power plant applications are compared on the basis of power requirement trends, working fluids, materials, and system requirements. The differences in Brayton and Rankine cycles, the requirements of the cycles imposed on turbines, and typical losses inherent in present low power space turbines are discussed. A comparison is made of representative present and future turbines for turbojet and space power applications. Future large space turbines will parallel the performance and design techniques of high performance gas turbines. Some of the design techniques of steam turbines can also be used because of experience with wet vapor and long endurance. The future goals and problem areas of turbojet and space turbines are shown.

This paper attempts to assess the benefits of a unique distributed propulsion concept, known as the Multi-Gas Generator Fan (MGGF) system, over conventional turbofan engines on civilian vertical takeoff and landing (VTOL) applications. The MGGF-based system has shown the potential to address the fundamental technical challenge in designing a VTOL aircraft: the significant mismatch between the power requirements at lift-off/hover and cruise. Vehicle-level performance and sizing studies were implemented using the Grumman Design 698 tilt-nacelle V/STOL aircraft as a notional personal air vehicle (PAV), subjected to hypothetical single engine failure (SEF) emergency landing requirements and PAV mission requirements.

A number of specimen life performance tests were conducted on three test lubricants selected to demonstrate their gross ranking capabilities. The results indicated that the test rigs should be used only for gross ranking. A large difference in magnitude of life values were obtained even though agreement in gross ranking was obtained by three out of the five participating laboratories. Further testing is recommended under preselected test conditions and lubricants.

The INTELSAT VIII / VIIIA program consists of six communication satellites (of two different designs) being produced by Lockheed Martin Astro Space for the International Telecommunications Satellite Organization (INTELSAT). Two spacecraft level thermal vacuum test facilities were required to test the first four spacecraft due to schedule constraints. The two facilities selected were the East Windsor, NJ (EW) 35 foot chamber and the 39 foot chamber at Lockheed Martin's Valley Forge, PA (VF) facility. INTELSAT 801 was tested in the EW 35 foot chamber which utilizes eight independently controlled shrouds to perform IR (hot wall) testing over an environmental temperature range of -180 to +80°C. INTELSAT 802 was tested in the VF 39 foot chamber which consists of shrouds flooded with LN2 at -180°C. Cal rods were used to independently control the thermal environments of the six spacecraft faces for this facility.

Due to ongoing efforts by the aviation industry, much has been learned over the last several years regarding jet engine power loss and compressor damage events caused by the ingestion of high concentrations of ice crystal particles into the core flow path. Boeing has created and maintained a database of such ice crystal icing (ICI) events to aid in analysis and further study of this phenomenon. This article provides a general update on statistics derived from the Boeing event database, and provides more details on specific event clusters of interest. A series of three flight campaigns have, over the past five years, collected in-situ data in deep convective clouds that will be used for the assessment of the new FAA CFR Part 33 ice crystal environmental envelope Appendix D, and the equivalent EASA CS-25 Appendix P.

The AiResearch TFE731-2 Turbofan Engine Control system was created out of a recognition of engine and aircraft operating requirements in which a free weighting of candidate control components and logic was made. From this free design iteration process, which considered both conventional and advanced concepts of control, the control described in this paper has evolved and has fulfilled the in-flight operating requirements of the engine.

Superoxides can be used in self-contained, emergency self-rescuers, both as sources of chemically stored oxygen and as carbon dioxide scrubbers. In the work described here, a single-pass flow-system test facility was employed to evaluate the reactivity of calcium superoxide, Ca(O2)2, with respiratory gases (H2O,CO2), in concentrations simulating exhaled breath. When compared with commercial preparations of potassium superoxide, KO2, 55–60% Ca(O2)2 was found to evolve oxygen and absorb carbon dioxide at significantly lower rates under conditions where each of the superoxides was reacted with 5% CO2 streams having dew points of 37°C. Whereas O2 evolution and CO2 absorption occurred simultaneously in the case of KO2 beds, CO2 absorption lagged O2 evolution when beds of Ca(O2)2 were reacted with moisture and CO2.

High thrust-to-weight gas turbine engine development experience has shown that future testing facilities must be more complex and have increased capability. This paper defines the requirements for such facilities and the parameters that generate them. These test facilities include hardware, support services, and performance assurance capability required to meet future needs. Comparisons are made between military specification and currently perceived contractor testing requirements for gas turbine engines, rotating components, and accessories to meet future military procurement expectations, along with the influence of development instrumentation measurement uncertainty.

This paper reports on the design, development, and use of a test rig that enables the analysis of the aggressivity of vehicle interiors to the heads of occupants. The equipment comprises a pneumatically controlled free-flight headform device. It can be positioned inside the passenger compartment of any passenger car via any normal window or door aperture. The device fires a simulated headform prescribed in SAE J984 at speeds for 10 to 30 mph. The enormous degree of flexibility in positioning enables impacts to be conducted on almost any part of the vehicle interior. Currently, energy-absorbing characteristics of the interior of passenger cars are assessed using drop rigs or pendulums, which necessitate the dismantling of the vehicle body. This has implications for representativeness in terms of the validity of the stiffness characteristics of the section of the vehicle being tested. The results of testing standard specimens, using all three test devices, are presented and discussed.

This Aerospace Information Report (AIR) is a general overview of typical airborne vibration monitoring (AVM) systems with an emphasis on system hardware design considerations. It describes AVM systems currently in use. The purpose of this AIR is to provide information and guidance for the selection, installation, and use of AVM systems and their elements. This AIR is not intended as a legal document but only as a technical guide.

This AIR is a general overview of typical airborne vibration monitoring (AVM) systems with an emphasis on system hardware design considerations. It describes AVM Systems currently in use.

Advances in avionics and display technology are significantly changing the cockpit environment in current transport aircraft. The MIT Aeronautical Systems Lab (ASL) has developed a part-task flight simulator specifically to study the effects of these new technologies on flight crew situational awareness and performance. The simulator is based on a commercially-available graphics workstation, and can be rapidly reconfigured to meet the varying demands of experimental studies. The simulator has been successfully used to evaluate graphical microburst alerting displays, electronic instrument approach plates, terrain awareness and alerting displays, and ATC routing amendment delivery through digital datalinks.

This Aerospace Recommended Practice (ARP) is a general overview of typical airborne engine vibration monitoring (EVM) systems applicable to fixed or rotary wing aircraft applications, with an emphasis on system design considerations. It describes EVM systems currently in use and future trends in EVM development. The broader scope of Health and Usage Monitoring Systems, (HUMS) is covered in SAE documents AS5391, AS5392, AS5393, AS5394, AS5395, AIR4174. This ARP also contains the essential elements of AS8054 which remain relevant and which have not been incorporated into Original Equipment Manufacturers (OEM) specifications.

This Aerospace Information Report (AIR) is a general overview of typical airborne engine vibration monitoring (EVM) systems applicable to fixed or rotary wing aircraft applications, with an emphasis on system design considerations. It describes EVM systems currently in use and future trends in EVM development. The broader scope of Health and Usage Monitoring Systems, (HUMS ) is covered in SAE documents AS5391, AS5392, AS5393, AS5394, AS5395, AIR4174.

This SAE Aerospace Information Report (AIR) is a general overview of typical airborne engine vibration monitoring (EVM) systems with an emphasis on system design considerations. It describes EVM systems currently in use and future trends in EVM development.