scholarly journals Some Details of Jet Engine Thrust

2016 ◽  
Vol 138 (09) ◽  
pp. 76-77
Author(s):  
Lee S. Langston
Keyword(s):  
Momentum Flux ◽  
Energy Input ◽  
Surface Forces ◽  
Second Law ◽  
Jet Engine ◽  
Engine Thrust ◽  
Blade Cascade ◽  
Engine Component ◽  
Airline Passengers ◽  
Frictional Forces

This article throws light on details of jet engine thrust. The momentum flux of the engine exiting flow is greater than that which entered, brought about by the addition of the energy input from combusted fuel, and giving rise to engine thrust. Thrust arises from pressure and frictional forces on these surfaces, e.g., blades, vanes, endwalls, ducts, etc. This interior force view of thrust is easy to visualize but quite another thing to actually measure. In doing research on secondary flow in gas turbine passages, researchers have measured both steady-state momentum changes and surface forces, in the much simpler case of a turbine blade cascade. The thrust values for each component in the Rolls-Royce single spool engine have been shown in this paper. It has been noted that from the compressor, gas path flow enters the engine case diffuser, where a pressure gain produces another component of forward thrust of 2,186 lbt. Newton’s second law of motion allows us to examine engine component behavior that exhibits both forward and rearward propelling forces, which results in the net thrust our airline passengers have purchased.

Thrust Nozzles for Supersonic Transport Aircraft

1964 ◽  
Vol 86 (2) ◽  
pp. 97-104 ◽  
Author(s):  
David Migdal ◽  
John J. Horgan
Keyword(s):  
External Flow ◽  
Operating Costs ◽  
Jet Engine ◽  
Transport Aircraft ◽  
Supersonic Transport ◽  
The Past ◽  
Engine Thrust ◽  
Performance Trends ◽  
Flow Effects ◽  
Plug Nozzles

Supersonic transports will require jet-engine thrust nozzles that are highly efficient from take-off to supersonic cruise in order to minimize the direct operating costs. Variable-area ejectors, plug nozzles, and modifications of these basic types have been tested extensively during the past several years. Performance trends for these nozzles are presented with the emphasis on external flow effects. A new ejector which utilizes aerodynamically actuated doors to admit external air into the ejector shroud is discussed.

Attitude control of nanosatellite with single thruster using relative displacements of movable unit

2020 ◽  
pp. 095441002095986
Author(s):  
Anton V Doroshin ◽  
Alexander V Eremenko
Keyword(s):  
Attitude Control ◽  
Center Of Mass ◽  
Angular Position ◽  
Main Body ◽  
Attitude Dynamics ◽  
Jet Engine ◽  
Engine Thrust ◽  
Body Change ◽  
Flexible Rods ◽  
Single Jet

The attitude dynamics of a nanosatellite (NS) with one movable unit changing its angular position relative to a main body of the nanosatellite is considered. This relative movability of the unit can be implemented with the help of flexible rods of variable length connecting the unit with the main body. Change of the relative position of the movable unit shifts the center of mass of the entire mechanical system. The NS has a single jet engine rigidly mounted into the NS main body. The shift of the mass center creates an arm of the jet-engine thrust and a corresponding control torque. Schemes to control the attitude dynamics of the satellite using the movability of its unit are developed, using both the torque from the engine and inertia change.

scholarly journals Nanoindentation, EPMA and Atom Probe Tomography Characterisation of Oxygen-rich Layer formed on a Titanium Jet Engine Component

2019 ◽  
Vol 25 (S2) ◽  
pp. 2534-2535
Author(s):  
HM Gardner ◽  
A Radecka ◽  
D Rugg ◽  
DEJ Armstrong ◽  
MP Moody ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Atom Probe ◽  
Jet Engine ◽  
Engine Component

Understanding the Thermodynamics of Biological Order

2012 ◽  
Vol 74 (1) ◽  
pp. 22-24 ◽  
Author(s):  
Jacob Peterson
Keyword(s):  
Information Processing ◽  
Energy Input ◽  
Growth Regulation ◽  
Second Law Of Thermodynamics ◽  
Life Cycles ◽  
Second Law ◽  
Complex Structures ◽  
Processing Capability ◽  
Open Thermodynamic Systems ◽  
Sunlight Energy

By growth in size and complexity (i.e., changing from more probable to less probable states), plants and animals appear to defy the second law of thermodynamics. The usual explanation describes the input of nutrient and sunlight energy into open thermodynamic systems. However, energy input alone does not address the ability to organize and create complex structures or explain life cycles – in particular, growth regulation and dying in the presence of adequate nutrients. Understanding the roles of macromolecules such as DNA, with their apparent information-processing capability, affords opportunity to understand biological order.

A Novel Mini Jet Engine Powered Unmanned Aerial Vehicle: Modeling and Control

2021 ◽  
pp. 1-13
Author(s):  
Erdinç Altuğ ◽  
Abdullah Türkmen
Keyword(s):  
Jet Engines ◽  
Flight Duration ◽  
Thrust Vectoring ◽  
Jet Engine ◽  
Modeling And Control ◽  
Engine Thrust ◽  
Heavy Lift ◽  
Aerial Vehicle ◽  
Thrust System ◽  
And Control

Significant progress has been made in recent years on personal air vehicles (PAVs), which offer independent and autonomous urban transportation. On-demand parcel delivery drones and heavy-lift drones are gaining serious attention. Although various designs for these systems have been put forward, they still have not reached sufficient maturity. The current systems provide somehow satisfactory operation, but many of these systems are limited in payload capacity and flight duration, and not suitable for future operations. In this paper, we propose a novel thrust system that uses multiple mini jet engines. Unlike electric motors, the jet engine thrust cannot vary rapidly. This led us to design and develop a thrust vectoring system for each jet engine. This proposed system has the potential to enable drones to carry more payload and achieve longer flight times. This paper discusses the design and modeling of the system as well as the stabilization algorithms that satisfactorily stabilize the proposed system. We presented that due to motor lag, thrust variations cannot stabilize the vehicle. We showed that the use of a thrust vectoring mechanism with LQR-based controller can overcome the effects of motor lag and stabilize the vehicle, successfully.

Jet Engine Component and Transducer Fault Diagnosis Using an Inverse Dynamic Model

2005 ◽  
Author(s):  
M. Lichtsinder ◽  
Y. Levy
Keyword(s):  
Fault Diagnosis ◽  
Inverse Dynamic ◽  
Fast Evaluation ◽  
Engine Operation ◽  
Inverse Dynamic Model ◽  
Jet Engine ◽  
Engine Model ◽  
Engine Component ◽  
Using Data ◽  
Real Time Simulations

Engine component and transducer degradation/fault diagnosis, are analyzed. The analysis is performed using an aero-thermodynamic nonlinear inverse jet-engine model while using data acquired during transient engine operation. A shortened inverse jet-engine model (without one or more engine component maps) was recently proposed by the authors for real-time simulations and for fast evaluation of engine component maps. The algorithm for the engine component’s fault diagnosis is significantly simplified using shortened inverse engine models. A diagnostic example of combined faults of a single transducer and a single engine component for a single spool jet engine is described using different combinations of shortened inverse jet engine models. In the present paper it is assumed that only a single transducer (out of the seven transducers) and /or a single engine component (compressor or turbine) fault could be present in the engine at a given time.

The Use of Probabilistic Reasoning to Improve Least Squares Based Gas Path Diagnostics

2006 ◽  
Vol 129 (4) ◽  
pp. 970-976 ◽  
Author(s):  
C. Romessis ◽  
Ph. Kamboukos ◽  
K. Mathioudakis
Keyword(s):  
Fault Diagnosis ◽  
Least Squares ◽  
Probabilistic Reasoning ◽  
Statistical Information ◽  
Least Square ◽  
Jet Engine ◽  
Engine Component ◽  
New Type ◽  
Component Faults ◽  
Health Parameters

A method is proposed to support least square type of methods for deriving health parameters from a small number of independent gas path measurements. The method derives statistical information using sets of solutions derived from a number of data records, to produce sets of candidate solutions with a lesser number of parameters. These sets can then be processed to derive an accurate component fault diagnosis. It could thus be classified as a new type of "concentrator" approach, which is shown to be more effective than previously existing schemes. The method's effectiveness is demonstrated by application to a number of typical jet engine component faults.

Structure Response of Cable-Stayed Bridge that Is Used with a Known Earthquake Spectrum

2011 ◽  
Vol 250-253 ◽  
pp. 3397-3400
Author(s):  
Yong Bin Ma ◽  
Yong Feng Du
Keyword(s):  
Modal Analysis ◽  
Spectrum Analysis ◽  
Time History ◽  
Time Dependent ◽  
Wave Loads ◽  
Jet Engine ◽  
Structure Response ◽  
Cable Stayed Bridge ◽  
Engine Thrust ◽  
History Analysis

A spectrum analysis is one in which the results of a modal analysis are used with a known spectrum to calculate displacements and stresses in the model. It is mainly used in place of a time-history analysis to determine the response of structures to random or time-dependent loading conditions such as earthquakes, wind loads, ocean wave loads, jet engine thrust, rocket motor vibrations, and so on. The paper is to analysis displacements and stresses of a cable-stayed bridge that is used with a known earthquake spectrum.

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