This paper describes an event-driven simulation tool for predicting particle-particle and particle-surface interactions in ice crystal icing (ICI). A new accretion model which is much less empirical than existing models for predicting ICI accretion is also described. Unlike previous models, the new “gouge/bounce model” (GBM) differentiates between (erosion) losses resulting from particle bounce and those resulting from particle gouging. A bounce threshold based on the tangential Stokes number is used to calculate most of the bounce loss. The GBM also predicts ejecta velocities and directions, at least approximately, which is important because most of the mixed-phase mass flux impacting a surface actually bounces off or erodes existing material in ICI, thereby increasing the mass flux downstream.
Recent studies have found that high mass concentrations of ice particles in regions of deep convective storms can adversely impact aircraft engine and air probe (e.g. pitot tube and air temperature) performance. Radar reflectivity in these regions suggests that they are safe for aircraft penetration, yet high ice water content (HIWC) is still encountered. The aviation weather community seeks additional remote sensing methods for delineating where ice particle (or crystal) icing conditions are likely to occur, including products derived from geostationary (GEO) satellite imagery that is now available in near-real time at increasingly high spatio-temporal detail from the global GEO satellite constellation.
Abstract More than a decade ago, we proposed combined use of direct injection (DI) and jet ignition (JI) to produce high efficiency, high power-density, positive-ignition (PI), lean burn stratified, internal combustion engines (ICEs). Adopting this concept, the latest FIA F1 engines, which are electrically assisted, turbocharged, directly injected, jet ignited, gasoline engines and work lean stratified in a highly boosted environment, have delivered peak power fuel conversion efficiencies well above 46%, with specific power densities more than 340 kW/liter. The concept, further evolved, is here presented for unmanned aerial vehicle (UAV) applications. Results of simulations for a new DI JI ICE with rotary valve, being super-turbocharged and having gasoline or methanol as working fuel, show the opportunity to achieve even larger power densities, up to 430 kW/liter, while delivering a near-constant torque and, consequently, a nearly linear power curve over a wide range of speeds.
This SAE Aerospace Information Report (AIR) has been written for individuals associated with ground level testing of turbofan and turbojet engines, and particularly for those who might be interested in investigating steady-state performance characteristics of a new test cell design or of proposed modifications to an existing test cell by means of numerical modeling and simulation. It is not the intent of this standard to provide specific test cell design recommendations, which are covered in the reference documentation.
SAE International has published a new recommended practice for assessing the amount of nonvolatile particulate matter (nvPM) that exits aircraft engine exhaust nozzles – ARP6481: Procedure for the Calculation of Non-Volatile Particulate Matter Sampling and Measurement System Losses and System Loss Correction Factors
Engineers at Boeing and NASA are collaborating on a lightweight, ultra-thin Transonic Truss-Braced Wing (TTBW) concept, designed to be more aerodynamic and fuel efficient than current designs, as part of the Subsonic Ultra Green Aircraft Research (SUGAR) program focusing on innovative aerospace concepts that reduce noise and emissions while enhancing performance.
This SAE Aerospace Information Report (AIR) supplements the AS755 performance station designation system for complex or unconventional propulsion cycles and their derivatives. The station numbering conventions presented herein are for use in all communications concerning propulsion system performance such as computer programs, data reduction, design activities, and published documents. They are intended to facilitate calculations by the program user without unduly restricting the method of calculation used by the program supplier. The contents of this document will follow AS755 and AS6502 where applicable. The list of symbols presented herein will be used for identification of input and output parameters. These symbols are not required to be used as internal parameter names within the engine subprogram.
Just down the road from SAE International’s headquarters in Warrendale, Pennsylvania, Mark Sokalski has been quietly working out how to maximize piston-driven engine efficiency – with an internal combustion engine mechanism that doesn’t follow the norm.
SAE International, a global association committed to being the ultimate knowledge source for mobility engineering, is bringing together subject-matter experts from across the globe for the first SAE International Aerospace Japan Symposium, held November 29 and 30 in conjunction with Japan International Aerospace Exhibition 2018 at Tokyo Big Sight convention center in Tokyo.
Weber Metals Inc., a division of Otto Fuchs KG of Germany, unveiled a new, $180 million, 60,000-ton press at its 2.5-acre facility in Paramount, California, southeast of Los Angeles. It sets a record as the highest tonnage hydraulic forging press in the Americas and the largest privately funded forging press investment in the world.
Hundreds of aerospace executives, engineers, scientists, and academics are gathering in London this week for Aerospace Systems and Technology Conference (ASTC) 2018 from SAE International in Warrendale, Pennsylvania. Discussions during the three-day industry event center on the theme of innovating air mobility. Aerospace thought leaders are at ASTC discussing current challenges, the latest enabling technologies, and future opportunities, including those related to urban air mobility (UAM) and supersonic aircraft.
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.
A new configuration of a rotary engine – the Szorenyi rotary engine – has been developed by the Melbourne-based Rotary Engine Development Agency (REDA). While the stator, or stationary part of the Szorenyi engine is similar to that of a Wankel engine, the geometric shape of the engine rotor is a rhombus, which deforms as it rotates inside the contour of the stator.
Pratt & Whitney was awarded the contract modification by the U.S. Air Force Life Cycle Management Center for the Adaptive Engine Transition Program. Through AETP, Pratt & Whitney was tasked with designing, fabricating, integrating, and testing complete, flight-weight adaptive engines – the contract modification allocates funding for “risk reduction” activities related to adaptive engine development.
Demand for high-performance plastics (HPPs) is up across the aerospace industry, driven by such key trends as growing performance requirements, increased use of additive manufacturing or 3D printing, supply chain globalization, and tightening environmental regulations. Growing passenger traffic coupled with the need to reduce emissions – being accomplished through lightweighting, engine downsizing, and vehicle electrification – present opportunities for HPPs, research analysts at Frost & Sullivan in San Antonio, Texas, explain.
Rolls-Royce in London is unveiling a concept electric vertical take-off and landing (EVTOL) vehicle, including civil and military variants, that could take to the skies as soon as the early 2020s. The flexible design – able to be adapted for a variety of applications, including personal transport, public transport, logistics, and defense – is based upon technologies currently in use and under development.
Aircraft orders exceed $95 billion in value and are complemented by roughly $3 billion in aircraft engine and engine service agreement contracts announced in the first two days of the 2018 Farnborough International Airshow. “The future starts at Farnborough; our exhibition halls are full of innovation that will shape how we fly, enabling us to go further, faster, and with less environmental impact,” says Farnborough International Commercial Director Amanda Stainer.
Standards development teams at SAE International in Warrendale, Pa., have issued 11 new technical documents and revised or reaffirmed another 54 technical reports focused on mobility engineering across the aerospace, automotive, and commercial transportation communities. The new documents, issued throughout June 2018, cover a variety of technical subject areas, including: diagnostic link connector security, mitigation strategies against illumination effects, data dictionary for quantities used in cyber physical exams, requirements for production of metal powder feedstock for use in additive manufacturing of aerospace parts, and laser powder bed fusion process.