scholarly journals Propulsion System Evaluation for an Unmanned High Altitude Long Endurance RPV

1991 ◽  
Author(s):  
Edward J. Kowalski ◽  
Norman C. Baullinger ◽  
Jennifer Kolden
Keyword(s):  
High Altitude ◽  
Propulsion System ◽  
Spark Ignition Engine ◽  
System Evaluation ◽  
Propulsion Systems ◽  
Atmospheric Sampling ◽  
Turboshaft Engine ◽  
Long Endurance ◽  
Rescue Drug ◽  
Selection Of

Unmanned High-Altitude Long-Endurance (HALE) aircraft have been studied for several years. Reconnaissance, surveillance, search and rescue, drug interdiction, atmospheric sampling, etc. are a few of the potential missions for HALE aircraft. One of the pacing technology items for an aircraft of this type is the propulsion system. This paper will discuss three candidate propulsion systems: a turbocompounded spark ignition engine, a recuperative turboshaft engine and a turbocharged turbocompounded diesel-turbine. HALE mission requirements dictate that certain parameters influence the selection of the propulsion system: propulsion system weight per horsepower, brake specific fuel consumption (lb/hr/shp), and reliability.

scholarly journals Liquid Cooled Turbocharged Propulsion System for HALE Application

1991 ◽  
Author(s):  
R. E. Wilkinson ◽  
R. B. Benway
Keyword(s):  
High Altitude ◽  
New Technology ◽  
Spark Ignition ◽  
Propulsion System ◽  
Spark Ignition Engine ◽  
Reciprocating Engine ◽  
Power Turbine ◽  
Significant Performance ◽  
Technical Assessment ◽  
Long Endurance

An unmanned air vehicle (UAV) capable of sustained flight in the upper limits of the tropopause is a relatively new technology which has seen increasing interest during the past decade. Mission lengths for High Altitude Long Endurance (HALE) applications are typically measured in days rather than hours with operating altitudes ranging from 50,000 to 100,000 feet. An Otto cycle propulsion system offers significant performance advantages over other cycles. This paper provides a technical assessment of a liquid cooled turbocharged, reciprocating engine concept capable of meeting the requirements for a HALE vehicle. A properly designed spark ignition engine with a two or three stage series turbocharger system utilizing state-of-the-art aerodynamic design can meet the challenges presented at these altitudes. Several records for long endurance and high altitude flight have already been set with this type of propulsion system. A comparison with other candidate engines will also be made. The ability to operate with low brake specific fuel consumption (BSFC) across a broad operating range will be identified. With sufficiently high exhaust gas temperatures, the addition of a power turbine for turbocompounding can further reduce the BSFC and brake specific air consumption (BSAC). A version of the turbocharged spark ignition engine is capable of providing high thermal efficiency with the least BSAC and minimum turbomachinery weight.

Analysis on Flight Dynamics of Solar UAV with Multiple Propulsion Systems

2011 ◽  
Vol 138-139 ◽  
pp. 453-458 ◽  
Author(s):  
Wei Xiao ◽  
Zhou Zhou
Keyword(s):  
Aspect Ratio ◽  
High Altitude ◽  
Flight Dynamics ◽  
System Efficiency ◽  
Large Aspect Ratio ◽  
Propulsion Systems ◽  
Obvious Effect ◽  
Modified Model ◽  
Distributed Propulsion ◽  
Long Endurance

High Altitude Long Endurance (HALE) Solar UAV is integrated with a series of motor-propeller propulsion systems along the large aspect-ratio wing. These systems have an obvious effect on the flight dynamics of the UAV. This paper established a model for the interaction between distributed propulsion systems and the flight dynamics of the airplane, it was used to improve the computation of the UAV’s flight quality, results with and without the modified model were compared. It was found that the large aspect-ratio wing integrated with distributed propulsion systems can change its stability significantly. According to the result, parameters of the propulsion systems are adjusted to optimize the flight quality and system efficiency.

scholarly journals Study and Assessment of Propulsion Systems of Three-Wheeled Electric Powered Rickshaw in India

2021 ◽  
Vol 9 (8) ◽  
pp. 1111-1117
Keyword(s):  
Automobile Industry ◽  
Building Materials ◽  
Propulsion System ◽  
Propulsion Systems ◽  
Ic Engine ◽  
Crucial Step ◽  
Power Drive ◽  
Metropolitan Cities ◽  
Vital Component ◽  
Selection Of

India is one of the prominent manufacturers in the automobile industry with 30 Million of vehicles production rate. Most of vehicles manufactured in India utilize internal combustion power drive methodology. Additionally, pollutions, global warming, conventional fuels exhaustion and loss of building materials are the major concerns associated with IC engine technology. Electric drive technology has the potential to mitigate these issues. Three-wheeled (3-W) battery powered rickshaws/vehicles are primarily employed for public conveyance in the metropolitan cities of India. The motor (propulsion) is a vital component of 3-W battery powered rickshaw. But, selection of appropriate propulsion system for 3-W rickshaw is crucial step. In the present study, an exertion has been prepared to assess the correct propulsion system for 3-W battery powered vehicle in Indian contest.

Simulation of a High Fidelity Turboshaft Engine-Alternator Model for Turboelectric Propulsion System Design and Applications

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
I. Yazar
Keyword(s):  
System Design ◽  
Electric Propulsion ◽  
Combustion Engine ◽  
Open Loop ◽  
Propulsion System ◽  
High Fidelity ◽  
Propulsion Systems ◽  
The Real ◽  
Hybrid Electric ◽  
Turboshaft Engine

Abstract The term sustainability became a popular subject both in the automotive industries and in the aerospace industries. Increasing and threatening environmental pollution problems and reduction in limited fuel sources are motivating either industries and academicians to develop alternative power systems to sustain more healthier and economical life in the long term. One innovation that has been researched in the automotive industry is all electric and hybrid electric propulsion concepts. These concepts have also been proposed as alternative solutions for aviation. These novel propulsion technologies are composed of a gas turbine/internal combustion engine structure (necessary for hybrid electric and turboelectric propulsion systems) and/or energy storage components (battery, fuel cell and so on.) with multiple electric motors respectively. In this paper, simulation of a high fidelity turboshaft engine-alternator model for turboelectric propulsion system is derived. To develop an aero-thermal engine model, GE T700 turboshaft engine data is used and constructed model is connected to an alternator model on MATLAB/Simulink environment. Open-loop simulations are carried out and satisfactory results are obtained.Simulation results are compared to the real engine design point data. Results show that there are acceptable differences between the simulation results and the real engine data. The power balances between compressor - high pressure turbine and power turbine – alternator are proven in the mathematical model. It is expected that the proposed model can be easily extended to power system design and power management studies in turboelectric propulsion systems and also in other suitable novel propulsion systems.

scholarly journals Propulsion Requirements for High Altitude Long Endurance Flight

1991 ◽  
Author(s):  
Roger W. Gallington
Keyword(s):  
High Altitude ◽  
Fuel Consumption ◽  
Propulsion System ◽  
Specific Power ◽  
Power Requirement ◽  
Active Involvement ◽  
Performance Requirements ◽  
And Control ◽  
Cooling Air ◽  
Long Endurance

This paper presents a set of general propulsion system performance requirements for high altitude long endurance flight. This flight objective places dramatically different values on fuel consumption, air consumption, system weight, and required heat rejection than the better understood range-payload objective. Some differences in overall vehicle design that suggest unusual propulsion systems are: (1) Optimum wing loadings for endurance at altitude are lower than acceptable for adequate wind penetration during descent and control during landing; (2) Compressing and cooling air at high altitudes requires large apparatus making specific air consumption very important; and (3) The lower specific power requirement and large fuel fractions make fuel consumption relatively more important than system weight. Based on the realistic expectations of aircraft aerodynamic performance and structural efficiency, the paper derives the correct propulsion system tradeoffs and extends these tradeoffs to include electrically-powered aircraft. A propulsion system designer can use the material presented here to guide the design of a high altitude long endurance propulsion system without active involvement of an airplane design team. The resulting propulsion design will be near-optimum.

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.

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