Browse Topic: Jet engines
A new aviation supply chain integrity coalition has offered 13 recommended actions to prevent the circulation of non-serialized aircraft parts throughout the global aviation industry. Embry-Riddle Aeronautical University, Daytona Beach, FL In the summer of 2023, a receiving clerk in the procurement department of TAP Air Portugal, a Lisbon-based airline, made a curious discovery: A $65 engine part that should have appeared brand-new showed signs of significant wear. The clerk checked the documentation from the London-based parts supplier and noticed that the submitted documentation was also suspicious. Using his safety training, the employee immediately reported the anomaly to TAP Air Portugal management, which raised the issue with the jet engine's manufacturer. Little did the procurement clerk know at the time, but this escalation led to one of the biggest investigations in the history of the aviation supply chain, as reported by Reuters and the British Broadcasting Corporation in
ABSTRACT PEO CS&CSS and CCDC GVSC, in partnership with Industry partners, are working to ensure the next generation of power generation sets and tactical wheeled vehicle systems maximize the usage of COTS, are compatible with Industry Standards, are supportable, and have growth potential to meet the needs of our Soldiers. Increasing regulations on emissions worldwide will impact commercial availability of high sulfur fuel / Jet Propulsion (JP)-8 compatible engines. It is recommended that the Army relook its regulation for JP-8 as the single fuel on the battlefield, in comparison to the potential cost of modifying COTS powertrains or procuring military unique engines in the next generation of tactical wheeled vehicles and power generation sets. The Army will realize additional performance with the ability to procure modern commercial powertrain technology, including potential improvements in power density and fuel efficiency. The Army should also consider operational requirements that
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 the performance characteristics of a new test cell design or of proposed modifications to an existing test cell by means of a scale model test
This Aerospace Information Report (AIR) is limited in scope to the general consideration of environmental control system noise and its effect on occupant comfort. Additional information on the control of environmental control system noise may be found in 2.3 and in the documents referenced throughout the text. This document does not contain sufficient direction and detail to accomplish effective and complete acoustic designs
Hypersonic flight vehicles have potential applications in strategic defence, space missions, and future civilian high-speed transportation systems. However, structural integration has significant challenges due to extreme aero-thermo-mechanical coupled effects. Scramjet-powered air-breathing hypersonic vehicles experience extreme heat loads induced by combustion, shock waves and viscous heat dissipation. An active cooling thermal protection system for scramjet applications has the highest potential for thermal load management, especially for long-duration flights, considering the weight penalty associated with the heavier passive thermal insulation structures. We consider the case of active cooling of scramjet engine structural walls with endothermic hydrocarbon fuel. We have developed a semi-analytical quasi-2D heat transfer model considering a prismatic core single cooling channel segment as a representative volume element (RVE) to analyse larger-scale problems. The model includes
The development of hypersonic missiles represents the most significant advancement of defense weaponry since the 1960s. However, they also pose unique challenges for both design and technology. The term “hypersonic” refers to any speed faster than five times the speed of sound, or above Mach 5. Modern hypersonic missile systems require extensive communications interconnects within a highly confined space. This space requirement creates a demand for solutions combining small form factor with reduced weight and rugged construction to withstand high vibration and impact conditions from deployment to target. Currently there are two types of hypersonic weapons. Hypersonic glide vehicles (HGVs), also known as boost-glide vehicles, typically launch from ballistic missiles and are released at a specific altitude, speed, and with the flight path tailored to a target without being powered. Hypersonic cruise missiles (HCMs) are powered all the way to their targets, flying at lower altitudes than
A team at NASA's Jet Propulsion Laboratory that's creating a snake-like robot for traversing extreme terrain is taking on the challenge with the mentality of a startup: Build quickly, test often, learn, adjust, repeat. Called EELS (short for Exobiology Extant Life Surveyor), the self-propelled, autonomous robot was inspired by a desire to look for signs of life in the ocean hiding below the icy crust of Saturn's moon Enceladus by descending narrow vents in the surface that spew geysers into space
An investigation into emissions differences and their correlations with differing combustion characteristics between F24 and Jet-A was conducted. Raw emissions data was taken from a single stage jet engine by a FTIR gas analyzer. Measurements of H2O, CO2, CO, NOx, and total hydrocarbon emissions (THC) were taken at 60K, 65K, and 70K RPM. At 70K RPM Jet-A and F-24 the emissions were similar at approx.: 4% H2O, 3% CO2, 970 PPM CO, 28 PPM NOx. Jet-A THC emissions were approx.: 1200 PPM THC, F24 THC emissions were lower by over 60%. The significantly lower amount of THC emissions for F24 suggests more complete combustion compared to Jet-A
Jet Propulsion Laboratory Pasadena, CA
Aerospace manufacturers know what it means to work with high stakes. Extremely tight tolerances, expensive materials and complicated processes define the industry. But few aerospace components are more critical - or more challenging - than the turbine discs that go into the hot side of jet engines. When machining these rotating components, everything must be correct, secure and reliable - not only to meet stringent surface integrity requirements, but also to avoid devastatingly expensive failures. A mistake that leads to a scrapped component can cost a manufacturer upward of $100,000, depending on when the mistake happened in the production process
Hybrid electric aircraft propulsion is an emerging technology that presents a variety of potential benefits along with technical integration challenges. Developing these new propulsion architectures with their complex control systems, and ultimately proving their benefit, is a multistep process. This process includes concept development and analysis, dynamic simulation, hardware-in-the-loop testing, full-scale testing, and so on. This effort is being revolutionized and indeed enabled by new digital tools that support increasing the technology readiness level throughout the maturation process. As part of this Digital Transformation, NASA has developed a suite of publicly available digital tools that facilitate the path from concept to implementation. This paper describes the NASA-developed tools and puts them in the context of control system development for hybrid electric aircraft propulsion. The three MATLAB®-based software packages are the Toolbox for the Modeling and Analysis of
In an application first, the physics of why the sky is blue is used to measure gas flows without obstructive sensors. A longstanding industry partnership between Virginia Polytechnic Institute and State University (Virginia Tech) and Pratt & Whitney has resulted in a new laser-optical technology that aims to revolutionize in-flight thrust measurement
There’s nothing more core to turbomachinery than moving fluid at increasingly high speeds and pressures. Whether we’re talking about industrial turbines, air breathing jet engines, or liquid-rocket space applications, the higher the pressure and the higher the flow rate, the better the performance
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 document defines and illustrates the process for determination of uncertainty of turbofan and turbojet engine in-flight thrust and other measured in-flight performance parameters. The reasons for requiring this information, as specified in the E-33 Charter, are: determination of high confidence aircraft drag; problem rectification if performance is low; interpolation of measured thrust and aircraft drag over a range of flight conditions by validation and development of high confidence analytical methods; establishment of a baseline for future engine modifications. This document describes systematic and random measurement uncertainties and methods for propagating the uncertainties to the more complicated parameter, in-flight thrust. Methods for combining the uncertainties to obtain given confidence levels are also addressed. Although the primary focus of the document is in-flight thrust, the statistical methods described are applicable to any measurement process. The E-33 Committee
The discovery of a new category of shape-memory materials — ceramic as opposed to metal — could open a new range of applications, especially for high-temperature settings, such as actuators inside a jet engine
An MIT-developed heat treatment aims to transform the microscopic structure of 3D-printed metals, making the materials stronger and more resilient in extreme thermal environments. The technique also aims to make it possible to 3D print high-performance blades and vanes for power-generating gas turbines and jet engines, which would enable improved fuel consumption and energy efficiency
Researchers at NASA’s Jet Propulsion Laboratory (JPL) are developing a novel microthruster that could provide easy-to-control propulsion during spaceflight. Using solid silver as the fuel source, this innovative microthruster provides thrust via electrospray without heating the fuel reservoir or transporting liquid metals. Instead of transporting a molten metal, this design transports metal ions via a solid electrolyte film
Turboprop aircraft have the capability of reversing thrust to provide extra stopping power during landing. Reverse thrust helps save the wear and tear on the brakes and reduces the landing distance under various conditions. The article explains a methodology to predict the disking drag (reverse thrust) from the Computational Fluid Dynamics (CFD) technique using Blade Element Momentum (BEM) theory and estimation of the same from high-speed taxiing trial (HSTT) and ground roll data for a turboprop aircraft using system identification techniques. One-dimensional kinematic equation was used for modeling the aircraft dynamics, and the error between measured and estimated responses was optimized using the Output Error Optimization Method (OEOM). The estimated propeller drag was matched with CFD predictions to arrive at a relation between the propeller blade pitch angle and throttle position. The present study also investigates the estimation of the braking friction coefficient from the
This SAE Aerospace Information Report presents the following factors that affect hydraulic pump life and performance: a The need to supply hydraulic fluid at the correct pressure and quality to the pump inlet port b Considerations for the pump output c Factors to be considered for the pump case drain lines d The mounting of the hydraulic pump e Hydraulic fluid properties, including cleanliness
This SAE Aerospace Information Report (AIR) is limited to the subject of aircraft fuel systems and the questions concerning the requirements for electrical bonding of the various components of the system as related to Static Electric Charges, Fault Current, Electromagnetic Interference (EMI) and Lightning Strikes (Direct and Indirect Effects). This AIR contains engineering guidelines for the design, installation, testing (measurement) and inspection of electrical bonds
This SAE Aerospace Information Report (AIR) describes procedures for calculating fuel consumption for civil jet airplanes through all modes of operation for all segments of a flight. Turboprop and piston airplanes, as well as helicopters or unconventional aircraft, are not included in this AIR. The principle purpose of these procedures is to assist model developers in calculating airplane fuel consumption in a consistent and accurate manner that can be used to address various environmental assessments including those related to policy decisions and regulatory requirements. This AIR is intended to directly support the emission calculations documented in AIR5715. The models described in this AIR are intended to be used from the start of the takeoff roll to the end of the ground roll; taxi fuel consumption models are not included. If modelers have access to higher fidelity methods, they should use those methods in lieu of the ones in this AIR
This SAE Aerospace Information Report (AIR) reviews the precautions that must be taken and the corrections which must be evaluated and applied if the experimental error in measuring the temperature of a hot gas stream with a thermocouple is to be kept to a practicable minimum. Discussions will focus on Type K thermocouples, as defined in National Institute of Standards and Technology (NIST) Monograph 175 as Type K, nickel-chromium (Kp) alloy versus nickel-aluminium (Kn) alloy (or nickel-silicon alloy) thermocouples. However, the majority of the content is relevant to any thermocouple type used in gas turbine applications
This SAE Aerospace Information Report (AIR) relates considerations for design test procedures and test data evaluation for qualification of tire spray deflection devices
Siemens Industry, Inc. Munich, Germany 1-800-743-6367
Zulu Pods Miami, FL 786-445-0540
Researchers developed a propulsion system that could pave the way for hypersonic flight, such as travel from New York to Los Angeles in less than 30 minutes. They developed a way to stabilize the detonation needed for hypersonic propulsion by creating a special hypersonic reaction chamber for jet engines
This document summarizes types of heat sinks and considerations in relation to the general requirements of aircraft heat sources, and it provides information to achieve efficient utilization and management of these heat sinks. In this document, a heat sink is defined as a body or substance used for removal of the heat generated by thermodynamic processes. This document provides general data about airborne heat sources, heat sinks, and modes of heat transfer. The document also discusses approaches to control the use of heat sinks and techniques for analysis and verification of heat sink management. The heat sinks are for aircraft operating at subsonic and supersonic speeds
Modern and future aircraft jet engines require increased thermal efficiency to extract the necessary energy during fuel consumption for high velocity flight. One way of improving engine efficiency is through the increase of the turbine’s temperature gradient or the difference between the hottest and coldest temperatures in the engine during operation
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