Browse Topic: Jet engines

Items (1,088)

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

08/14/2023

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

2025-01-003205/05/2023

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

01/02/2023

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.

Potential Applications of Fuel Cells in Air Mobility

2022-26-121605/26/2022

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

Hydrogen Fueled Aircraft Engines

2022-26-115605/26/2022

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

Hypersonic Bi directional Blended Wing Body UAV Conceptual Development.

2022-26-113705/26/2022

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

2022-26-115505/26/2022

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

2022-01-052503/29/2022

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)

09/10/2021

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

1316109/03/2021

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-3960708/01/2021

Turbojet Engine Parameters Calculation Based on Fuel Flow and Exhaust Gas Temperature

2021-01-002903/02/2021

The aircraft jet engine is one of the most complex multivariable systems with multiple inputs and multiple outputs. To attempt to optimize control functions or to address diagnostic problems, a detailed knowledge of all jet engine design parameters and performances is required. Although jet engines have been around for almost a century, there are only a few companies in the world presently designing and manufacturing them; as such these companies possess detailed knowledge of all relevant design characteristics and performance parameters. In the event where jet engine technical details are unknown, or only a few of them are known from manufacturer’s catalogues, the challenge becomes how to calculate and extrapolate critical performance parameters based on only fuel flow, jet exhaust temperature and total thrust. The brief engineering concept of calculation steps presented herein has the goal of identifying unknown turbojet engine parameters and design characteristics based on limited

Novakovic, Neno

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

AS5537A (Current)

02/10/2021

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)

02/01/2021

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