Browse Topic: Jet engines

Items (1,200)

A Review of Literature on the Relationship Between Gas Turbine Engine Lubricants and Aircraft Cabin Air Quality

11/26/2025

There has been a recent upsurge in interest from the media concerning the quality of the environment within aircraft cabins and cockpits especially in the commercial world. This has included (although by no means been limited to) the air quality, with particular reference to the alleged effects of contamination from the aircraft turbine lubricant. Possible exposure to 'organophosphates' (OPs) from the oil has raised special concerns from cabin crew. Such is the concern that government organisations around the world, including Australia, USA and UK, have set up committees to investigate the cabin air quality issue. Concern was also voiced in the aviation lubricants world at the way in which OP additives in turbine lubricants were being blamed in some reports for the symptoms being experienced by air crew and passengers. SAE Committee E-34 therefore decided that it should gather as much available information on the subject as possible. This would then enable E-34 to participate in

E-34 Propulsion Lubricants Committee

Experimental Evidence to Influence Design of Novel Low Lubrication Method for Rotorcraft Secondary Lubrication Systems

F-0081-2025-0279

5/20/2025

This paper presents experimental research aimed at developing novel low lubrication methods for rotorcraft and jet engines, focusing on sustaining minimal lubrication to prevent catastrophic bearing failure during loss of lubrication (LoL) events or to increase fuel consumption performance on once-through, fuel-oil bearing lubrication engines. Utilizing two high-speed bearing test rigs simulating low and high thrust class engine conditions, the study establishes lower bounds for oil flow rates necessary to maintain thermal stability and prevent thermal runaway in hybrid ball bearings. These findings inform the design of the Zulu Pod (ZPod), a passively driven, self-contained oil delivery system that uses engine compressor bleed air to precisely meter lubricant flow. Engine test stand results demonstrate that replacing traditional fuel-oil lubrication with the ZPod system reduces thrust specific fuel consumption (TSFC) by an average of 7%, with up to 11% savings, without compromising

Boersma, Pieter, Currier, Todd, Ferrante, Jason, Rosenthal, Julius

Performance Analysis of a High-Speed Tiltrotor Aircraft Featuring VerdeGo Aero's VH-5 Hybrid-Electric Turbofan Engine

F-0080-2024-1235

5/7/2024

In the pursuit of High-Speed Vertical Takeoff and Landing (HSVTOL) platforms, VerdeGo Aero offers its VH-5 hybrid-electric turbofan as the answer to missions requiring high power, vertical lift, and jet-like speeds. To evaluate the possibility of designing a real HSVTOL aircraft around VerdeGo's VH-5 powerplant, this paper investigates the size and expected performance of a militarized spinoff of NASA's Class B, High-Efficiency Civil TiltRotor (HECTR) concept, which has been renamed the VerdeGo Hybrid-Electric Combative TiltRotor, or "VHECTR" for short. Through an in-depth conceptual weight buildup of four commonly proposed tiltrotor architectures, this paper suggests that an entirely new, turbofan-driven propulsion system is needed if modern day HSVTOL demands are to be met. Hence, a separate, yet more conventional "Modified HECTR" tiltrotor configuration is considered to contest the proposed, VH-5 powered VHECTR concept. However, the results of a full-scale aircraft comparison

Roiati, Riccardo, Rice, Tyler, Steinfeldt, Brock, Nitzsche, Jasper, Anderson, Richard

Experimental and Numerical Investigation of Combustion and Noise, Vibrations, and Harshness Emissions in a Drone Jet Engine Fueled with Synthetic Paraffinic Kerosene

01-17-01-0006

8/14/2023

Emissions and effects of climate change have prompted study into fuels that reduce global dependence on traditional fuels. This study seeks to investigate engine performance, thermochemical properties, emissions, and perform NVH analysis of Jet-A and S8 using a single-stage turbojet engine at three engine speeds. Experimental Jet-A results were used to validate a CFX simulation of the engine. Engine performance was quantified using thermocouples, pressure sensors, tachometers, flow meters, and load cells fitted to the engine. Emissions results were collected using an MKS Multigas Emissions Analyzer that examined CO, CO₂, H₂O, NOx, and THC. NVH analysis was conducted using a multifield, free-field microphone, and triaxial accelerometer. This study found that Jet-A operates at higher temperatures and pressures than S8, and S8 requires higher fuel flow rates than Jet-A, leading to poorer efficiency and thrust. S8 produced stronger vibrations over 5 kHz compared to Jet-A. S8 showed a

Soloiu, Valentin, Mcafee, John, Ilie, Marcel, Rowell, Aidan, Willis, James, Dillon, Nicholas

Noise Reduction in High-Speed Sonic Under expanded jets using Slanted Perforated Tabs

2025-01-00325/5/2023

Studies on High-Speed Jet control is of prime importance to aerospace as well as related industries. Proper mixing of Jet of a fuel with the surrounding air is indispensable in the combustion chamber of a propulsive system, this contributes to the need of enhancing mixing of Jet with ambient air. The noise radiated by a jet engine is also a major problem for many cities around the world and this method also reduces the Jet associated noise which is of immense environmental concern for transport aircrafts. The High-speed Jet control is achieved by using two different methods. They are active Control method and passive control method. In active control method, the idea is to introduce stream wise vortices into the mixing layer of the jet. Passive control of the jet can be achieved by adding geometrical modifications. The present study deals with an innovative passive control of jet using slanted perforated tabs. which focuses on the method of changing the structures in turbulent free

R, Asad Ahmed, SUBRAMANIAN, THANIGAIARASU

Infrared Signature of Fixed and Variable Area C-D Nozzle of Aircraft Engine

01-16-02-0011

1/2/2023

The use of converging-diverging (C-D) variable area nozzle (VAN) in military aeroengines is now common, as it can give optimal expansion and control over engine back pressure, for a wide range of engine operations. At higher main combustion temperatures (desired for supercruise), an increase in the nozzle expansion ratio is needed for optimum performance. But changes in the nozzle throat and exit areas affect the visibility of engine hot parts as the diverging section of the nozzle is visible for a full range of view angle from the rear aspect. The solid angle subtended by engine hot parts varies with change in visibility, which affects the aircraft infrared (IR) signature from the rear aspect. This study compares the performances of fixed and variable area nozzles (FAN and VAN) in terms of engine thrust and IR signature of the engine exhaust system in the boresight for the same increase in combustion temperature. This study is performed for two cases: (i) variable throat area and

Baranwal, Nidhi, Mahulikar, Shripad P.

Hydrogen Fueled Aircraft Engines

2022-26-11565/26/2022

In the recent years, the climate change has become more devastating, and its continuing use of fossil fuels seems unreasonable as humankind is being pushed into a corner where the need to choose an alternative fuel has become necessary. The two main alternatives currently available are: Electrical propulsion and Hydrogen injected air breathing engines. Electrical propulsion had come far since last 10 years with Li+ ion technology, but the problem with them persists. They provide a low power to weight ratio which reduces the range as well as the load while operating the aircraft. On the other hand, Hydrogen with fuel cells or H2-O2 combustion has a high power to weight ratio but very difficult to handle. So, using hydrogen comes with a lot of difficulties in the present scenario. However. the concept of hydrogen has come a long way since its first use as a Rocket fuel. But this alternate fuel provides many advantages as well as challenges which needs to be overcome to move on its use in

Sri, Ratan, Sivamani, Seralathan

Potential Applications of Fuel Cells in Air Mobility

2022-26-12165/26/2022

The climate change impact due to increased greenhouse gas emissions like carbon dioxide (CO2), methane, nitrous oxide (NOx) and ozone etc. has been immense over the years and causing increase in temperatures of the earth’s surface and global warming. Recently, there is a significant effort to reduce the emissions especially after Paris agreement in 2015. There are several research initiatives across the globe to reduce the emissions like NOx, CO2 and other harmful substances. The air mobility also contributed to the increased greenhouse gases due to CO2 and NOx. This paper presents the potential applications of fuel cells for air mobility that includes helicopters, hybrid electric aircrafts and all electric aircrafts to achieve the reduced emissions and reduced fuel consumption. The objective of this paper is to take a broad view of how fuel cell technology works, various types of existing technologies and their potential applications and challenges for air mobility vehicles in terms

Kari, Sreedhar, Kumar, Ravi

Hypersonic Bi directional Blended Wing Body UAV Conceptual Development.

2022-26-11375/26/2022

This paper looks to develop a conceptual Hypersonic Bi-directional BWB UAV for high efficiency hypersonic systems.This concept successfully allows for many technical challenges involved in supersonic flight which are also present in hypersonic flight to be overcome; however some of these challenges become even greater, in addition to the new phenomena present at hypersonic speeds.The bi-directional BWB UAV concept consists of a symmetric planform which enables flight to occur at two different geometric configurations. The subsonic configuration would have a high aspect ratio and a low sweep and in the hypersonic configuration the UAV would then rotate 90 degrees which would have a low aspect ratio and high sweep. This design overcomes the inherent conflict between subsonic and hypersonic flight in conventional hypersonic launch systems.The airfoil of the subsonic configuration is thicker than that for the hypersonic configuration, a thick airfoil is needed to achieve a high lift

Fernandes, Shane

A Computational performance study on cheaper fuels for Micro Jet Engine as Jet A1 replacement without performance penalties

2022-26-11555/26/2022

Micro Jet Engines are used in UAVs, MAVs, and missiles increasingly. Even though they have a lower thermal efficiency, they have a higher thrust to weight ratio and endurance than electric motors. This lower thermal efficiency incurs expensive fuels and higher fuel consumption. The purpose is to test the performance of a designed Micro jet Engine with cheaper ethanol, kerosene, and automotive diesel. As diesel has a higher energy density and heating value than Jet A1, it outperforms jet a1. The ordinary refined kerosene is also tested. At a nominal air fuel ratio of 60, i.e., 1.5 g/s for this designed 0.086 kg/s engine air flow rate, all three fuels perform approximately the same in steady state simulations, as per steady state simulations : kerosene provides 2240 K, jet a1 provides 2311 K, the ethyl alcohol provides 2350 K and kerosene burns at 2274 K. These steady state simulation results is better for performance comparison between the fuels while for real time combustion exit

A, Adithya, Renald, C J Thomas

Effects of octane number and sensitivity on combustion of jet ignition engine

2022-01-05253/29/2022

Octane number (ON) and octane sensitivity (OS), the fuel anti-konck indexes, are critical for the design of advanced jet ignition engines. In this study, twelve fuels with different research octane number (RON) and varying OS were formulated based on ethanol reference fuels (ERFs) to investigate effects of OS on combustion of jet ignition engine. The results indicated that jet ignition decreased ON demand of the fuel when compared with spark ignition. For jet ignition, the knocking intensity increased with the increase of OS under the same ON. For fuels with high and medium RON fuels (RON=100 and RON=92), a medium OS ranging from 3 to 5 was more favorable to achieve higher thermal efficiency. Though ignition delay and combustion duration decreased with the increase of OS, the combustion efficiency and the knocking intensity limited thermal efficiency of the fuel. The behavior of OS made little difference under stoichiometric and lean burn. For fuels with high OS (OS>7), coefficient of

zhao, ziqing, cai, kaiyuan, wang, wei, Li, Yanfei

Aircraft Engine Life Cycle Cost Guide

AIR1939A (Current)

9/10/2021

AIR 1939 addresses communication of LCC data between equipment suppliers, aircraft engine producers, aircraft manufacturers, and users, as illustrated in Figure 1. The LCC data categories addressed include: research, development, test and evaluation (RDT&E); acquisition (initial procurement and investment); and operating and support (O&S) costs. While input and output formats are suggested, calculation procedures and cost methodology are specifically excluded since many LCC models preferred by the industry are company sensitive or proprietary (Figure 1). The relationship of LCC input data to program phase is described. Ground rules and assumptions are addressed. A glossary of LCC terms is provided. The LCC impact of propulsion systems on other aircraft systems is considered. This document was specifically developed for military propulsion system cost analysis. However, it is believed that a functional relationship exists between military and commercial Life Cycle Cost analysis and that

LCLS Life Cycle Logistics Supportability

SAE TOMORROW TODAY: Cleaner, Greener & Quieter: Transforming the Future of Flying

131619/3/2021

The best airplane can only be designed around the best engine - so says Pratt & Whitney, a Raytheon Technologies Company, where they've been transforming powered flight with an explorer's heart and a perfectionist's grit. Lisa Claveloux, Pratt & Whitney's Senior Director, Group Quality, tells the iconic brand's history, what impacts the pandemic has had on the aerospace industry, and the more sustainable footprint that their GTF engines bring to the skies. These revolutionary geared turbofan engines have already saved more than half a billion gallons of fuel and about five million metric tonnes of CO2, while also slashing aircraft noise footprint by 75%. Claveloux's passion for safety drew her to the work of the SAE ITC Aerospace Engine Supplier Quality (AESQ) strategy group. She discusses the challenges in the market, the gap the SAE AS13100 Standard fills, and why compliance is critical for enabling quality and making our skies safe for everyone.

Hineman, Marcie

Fine-Tuning Alloys for High-Temperature Use

TBMG-396078/1/2021

Weather Support to Deicing Decision Making (WSDDM) Winter Weather Nowcasting System

AS5537A (Current)

2/10/2021

The purpose of this SAE Aerospace Standard is to provide guidelines for the components and configurations that define the research and commercial versions of the Weather Support to Deicing Decision Making (WSDDM) winter weather nowcasting system.

G-12M Methods Committee

Design Considerations for Enclosed Turbofan/Turbojet Engine Test Cells

AIR4869B (Current)

2/1/2021

This SAE Aerospace Information Report (AIR) has been written for individuals associated with the ground-level testing of large and small gas turbine engines and particularly for those who might be interested in upgrading their existing or acquiring new test cell facilities.

EG-1E Gas Turbine Test Facilities and Equipment

Design Considerations for Enclosed Turbofan/Turbojet Engine Test Cells

AIR4869A (Historical)10/22/2020

EG-1E Gas Turbine Test Facilities and Equipment

Test Cell Instrumentation

AIR5026B (Current)10/21/2020

This document discusses, in broad general terms, typical present instrumentation practice for post-overhaul gas turbine engine testing. Production engine testing and engine development work are outside the scope of this document as they will typically use many more channels of instrumentation, and in most cases will have requirements for measurements that are never made in post-overhaul testing, such as fan airflow measurements, or strain measurements on compressor blades. The specifications for each parameter to be measured, in terms of measurement range and measurement accuracy, are established by the engine manufacturers. Each test cell instrument system should meet or exceed those requirements. Furthermore, each instrument system should be recalibrated regularly, to ensure that it is still performing correctly.

EG-1E Gas Turbine Test Facilities and Equipment

Modification of the Internal Flows of Thermal Propulsion Systems Using Local Aerodynamic Inserts

2020-01-20399/15/2020

Modern thermal propulsion systems (TPS) as part of hybrid powertrains are becoming increasingly complex. They have an increased number of components in comparison to traditionally powered vehicles leading to increased demand in packaging requirements. Many of the components in these systems relate to achieving efficiency gains, weight saving and pollutant reduction. This includes turbochargers and diesel or gasoline particulate filters for example and these are known to be very sensitive to inlet boundary conditions. When overcoming packaging requirements, sub-optimal flow distributions throughout the TPS can easily occur. Moreover, the individual components are often designed in isolation assuming relatively flat and artificially quiescent inlet flow conditions in comparison to those they are actually presented with. Thus, some of the efficiency benefits are lost through reduced component aerodynamic efficiency. Using local aerodynamic modification devices, StreamVaneTM, to eliminate

Butcher, Daniel, Gillespie, John, Walker, A. Duncan, Lowe, K. Todd, Spencer, Adrian

Ecological Comparison of Domestic Travel by Air and Road Transport

2020-01-21379/15/2020

The article describes issues related to the impact of transport means on the environment. These issues are currently very popular due to the increasing public awareness of the negative environmental and health effects associated with air pollution. The authors estimated specific emissions in passenger-kilometers, considering a domestic travel by air and road transport. The analyzed route is located between the Polish cities: Gdansk and Cracow. The selected route is long by domestic travel standards, but in that travel distance, the road transport is still competitive to the air transport. Selected means of transport belong to popular representatives in their classes. As a road vehicle, the authors selected a modern passenger car powered by a spark ignition engine, meeting the Euro 6 emission standard. Among the passenger aircrafts, an object which belongs small jet aircrafts, propelled with Rolls-Royce Tay 611C jet engines was selected. As the strength of this article, it is important

Nowak, Mateusz, Jasiński, Remigiusz

Parameterization of Particles Emitted from a Jet Engine during Stationary Tests

2020-01-22029/15/2020

Particles are one of the pollutants that affect air quality. The assessment of air pollution degree is conducted, among others, on the basis of parameters regarding the mass concentration of particles (PM2.5 and PM10). The growing awareness of the processes accompanying particles emissions is causing a growing interest in their other parameters such as number and diameter. Particles dimensions are important in determining their impact on human health. The most dangerous are particles of the smallest size; characteristic for internal combustion engines, mainly jet engines. The assessment of individual means of transport from the point of view of their ecological aspects is carried out in relation to fuel consumption, while in the case of particles; the analysis must be extended by their individual parameters. The article presents a comprehensive analysis of particles emissions from a jet engine during stationary tests. Selected engine work points represented individual stages of the LTO

Jasiński, Remigiusz

Determination of Costs and Benefits from Implementing an Engine Health Management System

ARP4176A (Current)4/28/2020

This ARP provides an insight into how to approach a cost benefit analysis (CBA) to determine the return on investment (ROI) that would result from implementing a propulsion Prognostics and Health Management (PHM) system on an air vehicle. It describes the complexity of features that can be considered in the analysis, the different tools and approaches for conducting a CBA and differentiates between military and commercial applications. This document is intended to help those who might not necessarily have a deep technical understanding or familiarity with PHM systems but want to either quantify or understand the economic benefits (i.e., the value proposition) that a PHM system could provide.

E-32 Aerospace Propulsion Systems Health Management

How to Install Coiled Spring Pins

TBMG-366044/1/2020

Limiting Creep in Aerospace Materials

TBMG-366134/1/2020

Limiting Creep in Aerospace Materials

20AERP04_044/1/2020

The Larson-Miller parameter was first used in the 1950s as a model to predict the lifetime of a material vs. time and temperature. Without close attention to materials selection, many products are not fit for purpose due to mechanical stress and natural creep. That's why creep resistant materials are so important in the aerospace industry. Materials under service conditions are required to sustain steady loads for prolonged periods of time and often undergo a time dependent deformation that is referred to as creep. Creep is the natural tendency of a material to gradually move or permanently deform as a result of mechanical stress or strain.

Coiled Spring Pins

20AERP04_014/1/2020

What Do They Do? How Do You Install Them? Of the hundreds of different types of fasteners used within the aerospace industry, the coiled spring pin was specifically invented as a solution to a “pinning” issue related to securing jet engine turbine blade assemblies back in the 1940s. No other fastener (pin, bolt, rivet, etc.) was strong enough to resist the forces generated during use that was also flexible enough to enable the pin to absorb shock and vibration to isolate the loads from the host material. It is this unique combination of strength and flexibility that enables the coiled pin to preserve the integrity of the hole and ensure that assemblies subject to dynamic loading stay intact. Today, coiled spring pins are used extensively throughout the aerospace industry for a wide variety of purposes. They are used to fasten two or more components together within evacuation slide mechanisms and cargo straps; they are used as hinge pins within interior latch mechanisms in overhead bin

Electronic Warfare Weapon

TBMG-360682/1/2020

MBDA Hertfordshire, UK +44 (0)1438 752000

Aircraft Engine Technology Review - The Pathways for an Efficient, Cleaner and Quieter Aviation Industry

2019-36-01751/13/2020

The aviation industry has been submitted to a set of environmental and commercial drivers that have led it to pursue engine technologies focused on the efficiency improvement, greenhouse (CO2) and pollutant (NOx and PM) emissions reductions, as well as noise abatement.The effort to comply with the ambitious long term environmental and efficiency targets set by the regulatory authorities has driven the aeronautic industry in a technological research effort. In the medium term, the aviation industry's strategy for commercial aviation is to focus on the advanced, but rather conventional propulsion systems (mainly turbofan engines). In this scenario, technological efforts have focused basically on enhancing thermal efficiency, through advanced core engines, as well as improving propulsive efficiency, through the use of low pressure systems (basically reduced pressure ratio and increased engine bypass ratio). To reach these objectives, a set of technological platforms has been proposed

Barbosa, Fábio Coelho

Metallization for SiC Semiconductors

TBMG-3570412/1/2019

Scientists at NASA’s Glenn Research Center have developed and patented improved ohmic contacts, and a fabrication method for them, that will speed the production of silicon carbide (SiC) sensors and electronics that operate in high-temperature, harsh environments.

Marking Aircraft Components

TBMG-3568312/1/2019

Numbers are critical to the smooth functioning of the international aerospace industry. Regulatory authorities such as the Federal Aviation Authority (FAA) and the US Department of Defense (DoD) mandate that aero components be permanently marked to ensure authenticity and traceability throughout the supply chain and into service.

Eddy Current Inspection of Circular Holes in Nonferrous Metallic Aircraft Engine Hardware

AS4787A (Current)10/14/2019

This SAE Aerospace Standard (AS) establishes minimum requirements for eddy current inspection of circular holes in nonferrous, metallic, low conductivity (less than 5% IACS) aircraft engine hardware with fasteners removed. The inspection is intended to be performed at maintenance and overhaul facilities on engine run hardware.

AMS K Non Destructive Methods and Processes Committee

Assessment of Numerical Cold Flow Testing of Gas Turbine Combustor through an Integrated Approach Using Rapid Prototyping and Water Tunnel

2019-28-005110/11/2019

In the present work, it is aimed at developing an integrated approach for combustor modeling involving rapid prototyping and water tunnel testing to assess the cold flow numerical simulations; the physical model will be subjected to cold flow visualization and parametric studies and CFD analysis to demonstrate its capability for undergoing rigorous cold flow testing. A straight through annular combustors is chosen for the present study because of it has low pressure drop, less weight and used widely in modern day aviation engines. Numerical Analysis has been performed using ANSYS-FLUENT. Three dimensional RANS equations are solved using k-ɛ model for the Reynolds numbers ranging from 0.64 x 105-1.5 x 105 based on the annulus diameter. Post processing the results is done in terms of jet penetration, formation of recirculation zone, effective mixing, flow split and pressure drop for different cases. Physical combustor models are fabricated using Rapid prototyping with Poly Lactic Acid

Senthilkumar, Sundararaj, Pugazhendhi, Ssheshan

Investigation of Machinability Characteristics on Turning of Nimonic 90A Using Al ₂ O ₃ and CNT Nanoparticle in Groundnut Oil

2019-28-007210/11/2019

Nimonic 90A alloy is a nickel-chromium-cobalt alloy and found as a potential material for turbine blades, discs, forgings, a ring section, and hot-working tools. This paper presents the effect of concentration along with cutting speed and feed rate on Fz: cutting force, Ra: surface roughness and Vba: tool wear with the application of two different nanofluids (NFS) on turning of Nimonic 90A by TiAlN PVD carbide cutting inserts. The nanoparticles suspended in oil taken for present investigation are nAl2O3, nCNT, and groundnut oil. The Taguchi L9 orthogonal array and derringer’s desirability response surface has been employed for parameter design and optimal search. 3D surface plots, factor effect plots, Taguchi S/N, and variance tests are used to study the effect of concentration on the machining performance of Nimonic 90A. The statistical analysis revealed % concentration for nCNT and cutting speed for nAl2O3 are found as an influenced parameter on performance characteristics. From the

Kannan, Venkatesan, Sundararajan, Devendiran

Landing Gear Integration into Aircraft Structure in Early Design Stage

2019-01-18909/16/2019

The demanded development towards various emission reduction goals set up by several institutions forces the aerospace industry to think about new technologies and alternative aircraft configurations. With these alternative aircraft concepts, the landing gear layout is also affected. Turbofan engines with very high bypass ratios could increase the diameter of the nacelles extensively. In this case, mounting the engines above the wing could be a possible arrangement to avoid an exceedingly long landing gear. Thus, the landing gear could be shortened and eventually mounted at the fuselage instead of the wings. Other technologies such as high aspect ratio wings have an influence on the landing gear integration as well. To assess the difference, especially in weight, between the conventional landing gear configuration and alternative layouts a method is developed based on preliminary structural designs of the different aircraft components, namely landing gear, wing and fuselage. Simplified

Kling, Ulrich, Hornung, Mirko

Compensating the Effects of Ice Crystal Icing on the Engine Performance by Control Methods

2019-01-18629/16/2019

Aircraft equipment is operated in a wide range of external conditions, which, with a certain combination of environmental parameters, can lead to icing of the engine internal elements. Due to icing, the engine components performance characteristics change what leads to decrease in thrust, gas dynamic stability, durability, etc. Safe aircraft operation and its desired performance may be lost as a result of such external influence. Therefore, it is relevant to study the possibilities of reducing the icing effect with the help of a special engine control. The focus of this paper is to determine control methods of an aircraft gas turbine engine addressing this problem. The object of the study is a modern commercial turbofan with a bypass ratio of about 9. In this paper analysis of the effect of ice crystal icing on the engine components performance is conducted. To perform simulation of the engine performance under such impact, degraded components characteristics was introduced into

Gurevich, Oskar, Smetanin, Sergei, Trifonov, Mikhail

Advanced Exergy Analysis of an Air Craft Gas Turbine Engine at Different Power Loading Operations

2019-01-18639/16/2019

The innovations in aircraft propulsion have been identified as the key parameter towards the progress in transportation. Continuous advancement in the performance and efficiency of propulsion has enabled aircraft to travel over larger distances with higher speed. Aviation is also responsible for approximately 2% of total greenhouse gas emission and is expected to grow around 3% by 2050. The present article aims to use the exergetic analysis of a turboprop engine which should be helpful in designing of such engines and also helps these engine users to regulate and select the operation modes. A gas turbine with film air cooling of turbine blades has been proposed to be the turboprop engine. The engine is analyzed on exergy point of view at different power loading operation modes and the performance is studied. Selected exergetic measures under consideration are Exergy Efficiency, Fuel Exergy Depletion Ratio, Relative Exergy Consumption Ratio, Exergetic Improvement potential and

Mohapatra, Alok Kumar, Hotta, Tapano, Choudhary, Tushar

Predictive CFD Auto-Tuning Approach for In-Cylinder Simulations of Two Small-Bore LDD Engines

2019-24-00339/9/2019

Tightening emission regulations and accelerating production cycles force engine developers to shift their attention towards virtual engineering tools. When simulating in-cylinder processes in commercial LDD DI engine development, the trade-off between run time and accuracy is typically tipped towards the former. High-fidelity simulation approaches which require little tuning would be desirable but require excessive computing resources. For this reason, industry still favors low-fidelity simulation approaches and bridges remaining uncertainties with prototyping and testing. The problem with low-fidelity simulations is that simplifications in the form of sub models introduce multi variable tuning parameter dependencies which, if not understood, impair the predictive nature of CFD simulations. In previous work, the authors have successfully developed a boundary condition dependent input parameter table. This parameter table showed outstanding results for lab-scale experiments for over 40

Nsikane, Daniel, Vogiatzaki, Konstantina, Morgan, Robert, Mustafa, Kenan, Ward, Andy

Aircraft Engine Icing Event Avoidance and Mitigation

TBMG-347387/1/2019

Innovators at NASA’s Glenn Research Center have developed a new means of avoiding and mitigating icing events for aircraft flying above 14,000 feet, dramatically improving aviation safety and reducing operating costs.

Scaling Evaluation of Ice-Crystal Icing on a Modern Turbofan Engine in PSL Using the COMDES-MELT Code

2019-01-19206/10/2019

This paper presents preliminary ice-crystal icing (ICI) altitude scaling evaluation results of a Honeywell Uncertified Research Engine (HURE) that was tested in the NASA Glenn Research Center Propulsion Systems Laboratory (PSL) during January of 2018. This engine geometry features a hidden core design to keep the core less exposed. The engine was fitted with internal video cameras to observe various ice buildup processes at multiple selected locations within the engine core flow path covering the fan stator, the splitter-lip/shroud/strut, and the high pressure compressor (HPC) variable inlet guide vane (IGV) regions. The potential ice accretion risk was pre-determined to occur by using NASA’s in-house 1D Engine Icing Risk assessment code, COMDES-MELT. The code was successful in predicting the risk of ice accretion in adiabatic regions like the fan-stator of the HURE at specific engine operating points. However at several operating points during the test, liquid water was observed

Tsao, Jen-Ching

The Effect of Crosswinds on Icing at Turbofan Engine Inlet

2019-01-20246/10/2019

Ice accretion at engine inlet has a dangerous effect on the inlet airflow and shed ice would be ingested into the engine and cause compressor blades damage, and even combustors flame out. In order to analyze the effect of crosswinds on icing at turbofan engine inlet, a complete icing analysis method, which is based on the Messinger model and takes the influence of runback water into consideration, is constructed. The runback water is considered laminar flow and the flow direction is dominated by the bottom flow of air. The supercooled water droplets impingement, ice accretion and runback water characteristics and inlet distortion with and without ice were investigated at crosswinds speed of 15, 20, 25, 30 kt. The variation of local water collection coefficient β is unchanged at crosswind conditions, but the location of the maximum value and non-dimensional impact limits change with the crosswind, which move backward along the outer edge on the windward, and move along the inner edge on

Yang, Qian, Guo, Zhiqiang, Zheng, Mei, Dong, Wei

Wind Tunnel Measurements of Simulated Glaciated Cloud Conditions to Evaluate Newly Developed 2D Imaging Probes

2019-01-19816/10/2019

Instrumentation that has been used for characterization of mixed-phase and glaciated conditions in the past, like the OAP probes, are subject to errors caused by variations in diffraction on the images away from the object plane and by the discrete nature of their particle detection and sizing. Correction methods are necessary to consider their measurements adequate for high ice water content (IWC) environments judged to represent a significant safety hazard to propellers and turbofan engine operability and performance. For this reason, within the frame of EU FP7 HAIC project, instrumentation characterization and validation is considered a major element need for successful execution of flight tests campaigns. Clearly, instrumentation must be sufficiently reliable to assess the reproducibility of artificial clouds with high ice water content generated in icing tunnels. Instruments are required to measure these conditions with a sufficient level of accuracy for the purposes of the

Esposito, Biagio M., Bachalo, William D., Leroy, Delphine, Schwarzenboeck, Alfons, Jurkat, Tina, Voigt, Christiane, Bansmer, Stephan

Numerical Investigation of the NASA Glenn Propulsion Systems Laboratory

2019-01-19246/10/2019

NASA Glenn Research Center’s Propulsion Systems Laboratory (PSL) allows ice-crystal ice accretion tests on jet engines. This pressurized wind tunnel facility allows engines to be operated at flight altitudes and temperatures. Steady state and unsteady computational fluid dynamics simulations were performed for the PSL geometry, including the spray bars with their supports, and the converging duct section. These simulation results help to characterize the performance of the tunnel and are important for understanding the flow and particle behavior leading up to the engine test section. The results indicate complex flow structures, with vortex shedding and non-uniform flow features. Flow separation is observed in several regions. Several flow features and vortices are seen to persist to the duct exit plane where the fan section of a jet engine would be mounted for testing. Unsteady simulations show that periodic vortex shedding is created by the spray bars, and that the generated

Feier, Ioan

Material Properties of Granular Ice Layers Characterized Using a Rigid-Body-Penetration Method: Experiments and Modeling

2019-01-20346/10/2019

Accretion and shedding of ice layers is a serious problem for various engineering applications. In particular, ice layers growing due to ice crystal impingement on warm parts of an aircraft jet engine pose a severe hazard since they seriously affect safe operation of an aircraft. The material properties, and in the first place the strength of an ice layer, are crucial for the mechanisms leading to, and taking place during, both accretion and shedding of an ice layer. In the present study, the apparent yield strength of dry granular ice layers is examined employing a novel rigid-body-penetration approach. Dynamic projectile penetration into granular ice layers of varying porosity and ice grain size is experimentally investigated for different projectile impact velocities using a high-speed video system and post-processing of the captured video data. The obtained data for the total penetration depth of the projectile is used to calculate the apparent yield strength of the ice layer based

Schremb, Markus, Malicevic, Kenan, Reitter, Louis, Roisman, Ilia, Tropea, Cameron

Ice-Crystal Icing Accretion Studies at the NASA Propulsion Systems Laboratory

2019-01-19216/10/2019

This paper describes an ice-crystal icing experiment conducted at the NASA Propulsion System Laboratory during June 2018. This test produced ice shape data on an airfoil for different test conditions similar to those inside the compressor region of a turbo-fan jet engine. Mixed-phase icing conditions were generated by partially freezing out a water spray using the relative humidity of flow as the primary parameter to control freeze-out. The paper presents the ice shape data and associated conditions which include pressure, velocity, temperature, humidity, total water content, melt ratio, and particle size distribution. The test featured a new instrument traversing system which allowed surveys of the flow and cloud. The purpose of this work was to provide experimental ice shape data and associated conditions to help develop and validate ice-crystal icing accretion models. The results support previous experimental observations of a minimum melt-ratio threshold for accretion to occur as

Struk, Peter M., Agui, Juan, Ratvasky, Thomas, King, Michael, Bartkus, Tadas, Tsao, Jen-Ching

Microwave Technique for Liquid Water Detection in Icing Applications

2019-01-19306/10/2019

The partial melting of ingested ice crystals can lead to ice accretion in aircraft compressors, but accurately measuring the relatively small fraction of liquid water content in such flows is challenging. Probe-based methods for detecting liquid water content are not suitable for deployment within turbofan engines, and thus alternatives are sought. Recent research has described approaches based on passive microwave sensing. We present here an approach based on active microwave transmission and reflection, employing a vector network analyzer. Utilization of both transmission and reflection provides additional data over and above emission or transmission only, and permits a more controllable environment than passive sensing approaches. The paper specifically addresses the question of whether such an approach is viable within the context of representative icing wind tunnel and engine flow conditions. A quasi-thermal equilibrium approach is presented herein to estimate the melting ratio

Leis, John, Buttsworth, David, Saeed, Ramiz, Saleh, Khalid, McGilvray, Matthew, Gillespie, David

A Continuing Investigation of Diurnal and Location Trends in an Ice Crystal Icing Engine Event Database

2019-01-19646/10/2019

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 most recent Boeing engine event study in 2015 focused on oceanic cloud systems that caused events in Southeast Asia, a region expected to have similar cloud properties as

Bravin, Melissa, Strapp, J. Walter

Semi-Empirical Modelling of Erosion Phenomena for Ice Crystal Icing Numerical Simulation

2019-01-19676/10/2019

The aim of this work is to develop a semi-empirical model for erosion phenomena under ice crystal condition, which is one of the major phenomena for ice crystal accretion. Such a model would be able to calculate the erosion rate caused by impinging ice crystals on accreted ice layer. This model is based on Finnie [1] and Bitter [2] [3] solid/solid collision theory which assumes that metal erosion due to sand impingement is driven by two phenomena: cutting wear and deformation wear. These two phenomena are strongly dependent on the particle density, velocity and shape, as well as on the surface physical properties such as Young modulus, Poisson ratio, surface yield strength and hardness. Moreover, cutting wear is mostly driven by tangential velocity and is more effective for ductile eroded body, whereas deformation wear is driven by normal velocity and is more effective for brittle eroded body. Several researchers based their erosion modelling on these two phenomena such as Hutchings et

Charton, Virgile, Trontin, Pierre, Aouizerate, Gilles, Villedieu, Philippe

Aerospace Work Platforms — More than Meets the Eye

TBMG-345456/1/2019

For maintenance personnel in the aerospace industry to do their jobs effectively, they need to be able to get physically close to the equipment they are working on. This statement sounds obvious, but in order to meet this requirement, it is very important to utilize quality work platforms. Although most people are familiar with the basic uses of work platforms, there is not always much thought given to everything that goes into their design and fabrication.

Aerospace Work Platforms - More than Meets the Eye

19AERP06_136/1/2019

Today's work platforms are far more complex than the simple designs of the past. For maintenance personnel in the aerospace industry to do their jobs effectively, they need to be able to get physically close to the equipment they are working on. This statement sounds obvious, but in order to meet this requirement, it is very important to utilize quality work platforms. Although most people are familiar with the basic uses of work platforms, there is not always much thought given to everything that goes into their design and fabrication. In years past, simple platforms were widely used for a variety of different work applications, however, much more is demanded of them in modern facilities. These increased demands have forced the work platform fabrication industry to evolve. The design and fabrication of today's platforms require manufacturers with expertise, experience, and skill. Fabricators and designers must incorporate specialized features in many areas never before seen or even

Design of Composite Materials for Improved Loss-of-Lubrication Survivability of Hybrid Rotorcraft Gears

F-0075-2019-14685

5/13/2019

Hybrid gears featuring steel teeth mated to a composite body provide the potential for significant weight savings in aerospace applications such as rotorcraft and geared turbofan engines. For hybrid gears to be viable for use in these applications, they must not degrade mechanical performance or thermal characteristics, particularly under loss-of- lubrication operation. The heat generated by loss-of-lubrication operation may be especially problematic for the fiber- reinforced polymer composite materials used in hybrid steel-composite gear prototypes. Initial hybrid gear design and testing is described in the literature, but no prior studies have investigated optimization of the composite material for thermal performance. In the study presented herein, conductive fibers and high-temperature polymers are introduced to make a composite material better suited to high-temperature and loss-of-lubrication. Channel-flow resin transfer molding was used to fabricate composites with a variety of

Waller, Matthew, Koudela, Kevin, McIntyre, Sean

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