PRELIIIINARY DESIGN OF TURBOFAN ENGINE PROPULSION SYSTEM ON MODERN FUEL EFFICIENT AIRCRAFT

1983 ◽  
Author(s):  
H.D. SOWERS ◽  
W. TABAKOFF
Keyword(s):  
Propulsion System ◽  
Turbofan Engine

Operating Characteristics of an Electrically Assisted Turbofan Engine

2020 ◽  
Author(s):  
Merijn Rembrandt van Holsteijn ◽  
Arvind Gangoli Rao ◽  
Feijia Yin
Keyword(s):  
Electric Propulsion ◽  
Propulsion System ◽  
Operating Characteristics ◽  
Turbofan Engine ◽  
Electric Propulsion System ◽  
Fuel Burn ◽  
Parallel Hybrid ◽  
Electrical Propulsion ◽  
Hybrid Electric ◽  
Cruise Flight

Abstract With the growing pressure to reduce the environmental footprint of aviation, new and efficient propulsion systems must be investigated. The current research looks at the operating characteristics of a turbofan engine in a parallel hybrid-electric propulsion system. Electric motors are used to supply power in the most demanding take-off and climb phases to achieve the required thrust, which allows the turbofan to be redesigned to maximize the cruise performance (to some extent). It was found that the turbofan’s cruise efficiency can be improved by 1.0% by relaxing the constraints of take-off and climb. It was found that the surge margins of compressors limit the amount of power that could be electrically supplied. On a short-range mission, the hybrid-electric propulsion system showed a potential to reduce around 7% of fuel burn on an A320 class aircraft. Most of these savings are however achieved due to fully electric taxiing. The weight of the electrical propulsion system largely offsets the efficiency improvements of the gas turbine during cruise flight. A system dedicated for fully electric taxiing system could provide similar savings, at less effort and costs. Given the optimistic technology levels used in the current analysis, parallel hybrid-electric propulsion is not likely to be used in the next-generation short to medium range aircraft.

A new solution to the coupled problems of aero-propulsion system deceleration under supersonic state

2021 ◽  
pp. 095440622110528
Author(s):  
Fengyong Sun ◽  
Chunsheng Ji ◽  
Tengfei Zhang
Keyword(s):  
Integrated Control ◽  
Control Variable ◽  
Propulsion System ◽  
Effective Control ◽  
Coupled Problems ◽  
Component Level ◽  
Turbofan Engine ◽  
Control Scheme ◽  
Level Model ◽  
Rapid Drop

Under supersonic state, the aero-propulsion system exhibits different coupled characters in deceleration from that in acceleration. However, the deceleration control has not been fully studied. In order to solve the coupled problems, an integrated component-level model including inlet and turbofan engine was established. Based on the integrated model, the particularity of inlet adjustment during deceleration was analyzed. And the analyzed results showed that the inlet regulation is not necessary to keep the inlet and engine working in well-matched at any time under supersonic state. Due to the coupled relationship between inlet and turbofan engine, a new optimal integrated control scheme is proposed in this paper. The inlet ramp angle is taken as an optimal control variable as the same as main fuel mass flow and nozzle throat area. The simulation results indicate that inlet ramp angle regulation showed a more effective control quality in the rapid drop of aero-propulsion–installed thrust. Furthermore, the deceleration could be completed in a shorter control time.

Steady Performance Measurements of a Turbofan Engine With Inlet Distortions Containing Co- and Counter-Rotating Swirl From an Intake Diffuser for Hypersonic Flight

2000 ◽  
Author(s):  
Norbert R. Schmid ◽  
Dirk C. Leinhos ◽  
Leonhard Fottner
Keyword(s):  
Low Frequency ◽  
Engine Performance ◽  
Propulsion System ◽  
Performance Measurements ◽  
Turbofan Engine ◽  
Frequency Measurements ◽  
Hypersonic Aircraft ◽  
Inhomogeneous Flow ◽  
Left And Right ◽  
Unsteady Performance

The influence of distorted inlet flow on the steady and unsteady performance of a turbofan engine which is a component of an airbreathing combined propulsion system for a hypersonic transport aircraft is reported in this paper. The performance and stability of this propulsion system depends on the behavior of the turbofan engine. The complex shape of the intake duct causes inhomogeneous flow at the engine inlet plane, where total pressure and swirl distortions are present. The S-bend intakes are installed axisymmetrically left and right into the hypersonic aircraft hence generating axisymmetrical mirror inverted flow patterns. Since all turbo engines of the propulsion system have the same direction of rotation, one distortion corresponds to a co-rotating swirl at the low pressure compressor (LPC) inlet while the mirror inverted image counterpart represents a counter-rotating swirl. Therefore the influence of the distortions on the performance and stability of the ‘CO’ and ‘COUNTER’ rotating turbo engine are differing, respectively. Both distortions were generated separately by an appropriate simulator at the inlet plane of a LARZAC 04 engine. The results of low frequency measurements at different engine planes yield the relative variations of thrust and specific fuel consumption and hence the steady engine performance. High frequency measurements were used to investigate the different influence of CO and COUNTER inlet distortions on the development of LPC instabilities.

Steady Performance Measurements of a Turbofan Engine With Inlet Distortions Containing Co- and Counterrotating Swirl From an Intake Diffuser for Hypersonic Flight

2000 ◽  
Vol 123 (2) ◽  
pp. 379-385 ◽  
Author(s):  
Norbert R. Schmid ◽  
Dirk C. Leinhos ◽  
Leonhard Fottner
Keyword(s):  
Low Frequency ◽  
Engine Performance ◽  
Propulsion System ◽  
Performance Measurements ◽  
Turbofan Engine ◽  
Frequency Measurements ◽  
Hypersonic Aircraft ◽  
Inhomogeneous Flow ◽  
Left And Right ◽  
Axisymmetric Mirror

The influence of distorted inlet flow on the steady and unsteady performance of a turbofan engine, which is a component of an air-breathing combined propulsion system for a hypersonic transport aircraft, is reported in this paper. The performance and stability of this propulsion system depend on the behavior of the turbofan engine. The complex shape of the intake duct causes inhomogeneous flow at the engine inlet plane, where total pressure and swirl distortions are present. The S-bend intakes are installed axisymmetrically left and right into the hypersonic aircraft, generating axisymmetric mirror-inverted flow patterns. Since all turbo engines of the propulsion system have the same direction of rotation, one distortion corresponds to a corotating swirl at the low pressure compressor (LPC) inlet while the mirror-inverted image counterpart represents a counterrotating swirl. Therefore the influence of the distortions on the performance and stability of the ‘CO’ and ‘COUNTER’ rotating turbo engine are different. The distortions were generated separately by an appropriate simulator at the inlet plane of a LARZAC 04 engine. The results of low-frequency measurements at different engine planes yield the relative variations of thrust and specific fuel consumption and hence the steady engine performance. High-frequency measurements were used to investigate the different influence of CO and COUNTER inlet distortions on the development of LPC instabilities.

scholarly journals Performance analysis of an electrically assisted propulsion system for a short-range civil aircraft

2018 ◽  
Vol 233 (4) ◽  
pp. 1490-1502 ◽  
Author(s):  
A W X Ang ◽  
A Gangoli Rao ◽  
T Kanakis ◽  
W Lammen
Keyword(s):  
Simulation Model ◽  
Power Management ◽  
Management Strategy ◽  
Short Range ◽  
Propulsion System ◽  
Aviation Industry ◽  
Electrical System ◽  
Turbofan Engine ◽  
Power Management Strategy ◽  
Electrically Assisted

With civil aviation growing at around 4.7% per annum, the environmental footprint of aviation is increasing. Moreover, the use of kerosene as a fuel accelerates the depletion of non-renewable fossil fuels and increases global warming. Hence, the aviation industry has to come up with new technologies to reduce its environmental impact and make aviation more sustainable. An electrically assisted propulsion system can combine the benefits of an electrical power source with a conventional turbofan engine. However, the additional electrical system increases the weight of the aircraft and complexity of the power management system. The objective of this research is to analyze the effect of an assistive electrical system on the performance of a turbofan engine for an A320 class aircraft on a short-range mission. The developed simulation model consists of an aircraft performance model combined with a propulsion model. The power management strategy is integrated within the simulation model. With the proposed propulsion system and power management strategy, the electrically assisted propulsion system would be able to reduce fuel burn, total energy consumption, and emissions for short-range missions of around 1000 km.

scholarly journals Evaluation of Potential Engine Concepts for a High Altitude Long Endurance Vehicle

1988 ◽  
Author(s):  
Edward J. Kowalski
Keyword(s):  
High Altitude ◽  
Propulsion System ◽  
Turbofan Engine ◽  
Counter Rotation ◽  
Long Endurance ◽  
Bypass Ratio

A potential need has been identified for a High Altitude Long Endurance (HALE) aircraft to augment current surveillance and engagement capability. HALE platforms offer mission flexibility and survivability which can complement ground based surveillance and engagement systems. Current mission requirements include a loiter altitude of 45,000 to 60,000 feet and a loiter time of 12 to 24 hours. The HALE aircraft will also be required to carry a sensor payload weight between 50,000 and 100,000 pounds. This paper will evaluate the potential of several propulsion system candidates. Engines to be examined include the “classical” turbofan engine with bypass ratios up to eight, the “ultra high bypass ratio” turbofan with bypass ratios up to 20, General Electric’s Unducted Fan (UDF) and the turboprop in a pusher and tractor configuration with single and counter rotation propfans.

Response of an Operational Turbofan Engine to a Simulated Nuclear Blast

1987 ◽  
Vol 109 (2) ◽  
pp. 121-129 ◽  
Author(s):  
M. G. Dunn ◽  
C. Padova ◽  
R. M. Adams
Keyword(s):  
Shock Waves ◽  
Transient Response ◽  
Incident Shock ◽  
Blast Waves ◽  
Propulsion System ◽  
Maximum Speed ◽  
Turbofan Engine ◽  
Air Breathing ◽  
Ludwieg Tube ◽  
Yaw Angle

This paper describes the results of a measurement program designed to determine the transient response of an air-breathing propulsion system to simulated nuclear blast waves. A Ludwieg-tube facility, incorporating a driver technique consisting of an activating chamber and a nonfrangible diaphragm, was used to create the required shock waves. Detailed measurements were performed at incident shock overpressures of approximately 6.9, 10.3, 13.8, and 17.2 kPa (1.0, 1.5, 2.0, and 2.5 psi). For each of these overpressures, data were obtained for engine speeds of 0, 80, 90, and 100 percent of maximum speed. Typical results are presented for distortion patterns at the fan face for both an extended bellmouth and a S-shaped inlet at either 0 or 20 deg yaw angle.

Turboelectric Distributed Propulsion System As a Future Replacement for Turbofan Engines

2017 ◽  
Author(s):  
Borys Łukasik
Keyword(s):  
Technological Development ◽  
Thermodynamic Cycle ◽  
Practical Method ◽  
Propulsion System ◽  
Propulsive Efficiency ◽  
Turbofan Engine ◽  
Turbofan Engines ◽  
Advantages And Disadvantages ◽  
Distributed Propulsion ◽  
Extra Weight

The main purpose of this paper is to discuss the possibility of standard turbofan engine replacement by the turboelectric distributed propulsion system, in future commercial aviation. Paper describes how the distributed propulsion allows to reach significantly greater propulsive efficiency than state-of-the-art high bypass turbofan engines, and presents turboelectric system as the only practical method of distributed propulsion implementation. However, since extra weight of the electric components that would be added can overcome the high propulsive efficiency benefit, a detailed analysis is needed to verify the feasibility of such system. This article shows results of such analysis that was conducted for 90 PAX class regional jet. Thermodynamic cycle calculations, performed for both, turbofan engine and turboelectric distributed propulsion are presented. They prove that distributed propulsion is able to provide great reduction in fuel consumption of uninstalled propulsion system, while performed mission analysis depicts the penalty of extra mass of electric appliances, showing actual profits that are achievable. On this example, advantages and disadvantages of the turboelectric distributed propulsion system in comparison with modern turbofan engines are discuss, taking into account the potential technological development of turbofan engine and additional non-propulsive benefits that turboelectric system is able to provide. Finally, this document also presents mass estimations for different scenarios of electric appliances evolution, which highlight the technology levels that need to be achieved before the system can be introduced in commercial service.

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