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 Advanced Turboprop Engines for Long Endurance Naval Patrol Aircraft

1982 ◽  
Author(s):  
R. Hirschkron ◽  
R. H. Davis
Keyword(s):  
Pressure Drop ◽  
Fuel Consumption ◽  
Pressure Ratio ◽  
Specific Fuel Consumption ◽  
Performance Requirements ◽  
The Future ◽  
Weight Design ◽  
Long Endurance

Long endurance naval patrol aircraft of the future will require more efficient advanced turboprop powerplants. Engines used in this kind of application will have performance requirements emphasizing prolonged endurance and very low specific fuel consumption for cruise and part-power loiter operation. Regenerative, regenerative/intercooled and advanced conventional cycle screening studies were carried out to select the cycle pressure ratio and turbine temperature for each type, considering the effects on installed performance and weight. Design and cycle choices were studied in each engine category including recuperator types, effectiveness, pressure drop, bypass bleed and variable area turbine nozzle. The engine characteristics of each type were then compared using a representative mission. The advanced conventional engine showed the largest potential, the regenerative second and the regenerative/intercooled the least promise for lower installed fuel consumption and improved mission performance.

Analysis of emissions from various driving cycles based on real driving measurements obtained in a high-altitude city

2020 ◽  
Vol 234 (6) ◽  
pp. 1563-1571 ◽  
Author(s):  
Meng Lyu ◽  
Xiaofeng Bao ◽  
Yunjing Wang ◽  
Ronald Matthews
Keyword(s):  
High Altitude ◽  
Real World ◽  
Vehicle Emissions ◽  
Control Strategies ◽  
Driving Cycle ◽  
Specific Power ◽  
Test Cycle ◽  
Light Duty ◽  
And Control ◽  
Light Duty Vehicles

Vehicle emissions standards and regulations remain weak in high-altitude regions. In this study, vehicle emissions from both the New European Driving Cycle and the Worldwide harmonized Light-duty driving Test Cycle were analyzed by employing on-road test data collected from typical roads in a high-altitude city. On-road measurements were conducted on five light-duty vehicles using a portable emissions measurement system. The certification cycle parameters were synthesized from real-world driving data using the vehicle specific power methodology. The analysis revealed that under real-world driving conditions, all emissions were generally higher than the estimated values for both the New European Driving Cycle and Worldwide harmonized Light-duty driving Test Cycle. Concerning emissions standards, more CO, NOx, and hydrocarbons were emitted by China 3 vehicles than by China 4 vehicles, whereas the CO2 emissions exhibited interesting trends with vehicle displacement and emissions standards. These results have potential implications for policymakers in regard to vehicle emissions management and control strategies aimed at emissions reduction, fleet inspection, and maintenance programs.

Study and Simulation on the Energy Efficiency Management Control Strategy of Ship Based on Clean Propulsion System

2015 ◽  
Author(s):  
Kai Wang ◽  
Xinping Yan ◽  
Yupeng Yuan
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Control Strategy ◽  
Control Strategies ◽  
Management Control ◽  
Propulsion System ◽  
Power Requirement ◽  
Doubly Fed ◽  
System Configurations ◽  
And Control

Nowadays, with the higher voice of ship energy saving and emission reduction, the research on energy efficiency management is particularly necessary. Energy efficiency management and control of ships is an effective way to improve the ship energy efficiency. In this paper, according to the new clean propulsion system configurations of 5000 tons of bulk carrier, the energy efficiency management control strategy of the clean propulsion system is designed based on the model of advanced brushless doubly-fed shaft generator, propulsion system using LNG/diesel dual fuel engine and energy consumption of the main engine for reducing energy consumption. The simulation model of the entire propulsion system and the designed control strategy were designed. The influence of the engine speed on the ship energy efficiency was analyzed, and the feasibility of the energy efficiency management control strategies was verified by simulation using Matlab/Simulink. The results show that the designed strategies can ensure the power requirement of the whole ship under different conditions and improve the ship energy efficiency and reduce CO2 emissions.

Stability and Control of a High-Altitude, Long-Endurance UAV

2007 ◽  
Vol 30 (3) ◽  
pp. 713-721 ◽  
Author(s):  
Ilhan Tuzcu ◽  
Pier Marzocca ◽  
Enrico Cestino ◽  
Giulio Romeo ◽  
Giacomo Frulla
Keyword(s):  
High Altitude ◽  
Stability And Control ◽  
And Control ◽  
Long Endurance

High Altitude Recuperated 50 kWe Turboprop Study

2008 ◽  
Author(s):  
Colin Rodgers
Keyword(s):  
High Altitude ◽  
Gas Turbine ◽  
Fuel Consumption ◽  
Sea Level ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Light Weight ◽  
Air Breathing ◽  
Air Inlet ◽  
Long Endurance

Specialized requirements exist for advanced high altitude unmanned air vehicles (UAV’s) capable of extended durations the propulsion units of which can only be served by either air-breathing highly turbocharged piston, and or, gas turbines engines with high thermal efficiency and light weight. These UAV requirements encompass ground surveillance, air sampling, and global atmospheric missions proposed in a variety of roles previously performed by larger manned aircraft. Some applications demand up to several days loitering endurance at altitudes over 65000ft, with which existing production propulsion engines are either incapable of meeting or require extensive modifications. Highly turbocharged piston engines and low specific fuel consumption turbofans have been developed for these specialized duties and record breaking global circumnavigation piloted aircraft. Recuperated cycle gas turbines thermal efficiencies of the order 40% are necessary to match those of current highly turbocharged piston engines which are difficult to attain with conventional uncooled metallic turbine rotors even at standard sea level day conditions. It is believed however that above the tropopause with sub zero air inlet temperatures, thermal efficiencies of 40% can rationally be attained with small relatively light weight recuperated gas turbine turboprops. The performance details and flowpath configuration of a two candidate recuperated turboprop designs are presented as specifically optimized for the propulsion of a long endurance UAV operating at 65000ft altitude, fueled with hydrogen.

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 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.

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.

Applying a distributed collaborative MDAO environment to study the power matching of the propulsion system and the on-board electrified systems for advanced regional and short- to medium-range jetliners

2019 ◽  
Vol 123 (1268) ◽  
pp. 1618-1638
Author(s):  
M. Fioriti ◽  
A. Mirzoyan ◽  
A. Isianov
Keyword(s):  
Beneficial Effect ◽  
Fuel Consumption ◽  
Propulsion System ◽  
Specific Fuel Consumption ◽  
Power Requirement ◽  
System Architectures ◽  
Power Matching ◽  
Electric Aircraft ◽  
Medium Range ◽  
More Electric Aircraft

ABSTRACTThis paper deals with the study of the power matching of the propulsion system and on-board systems changing the on-board systems’ electrification level. In particular, four system architectures have been studied, each one with a different level of electrification starting from the More Electric Aircraft (MEA) to the All Electric Aircraft (AEA) systems. The mass and the power requirement of each system architectures have been analysed together with the change in engine specific fuel consumption. Then, these results have been used to quantify the influences of engine and systems power matching to the entire aircraft. In particular, the beneficial effect of system electrification has been evaluated as an increment of aircraft range. Moreover, two reference aircraft – a regional jet and a short/medium range liner – have been selected to understand the variance of the power matching changing aircraft dimensions and mission range. The study is carried out using a distributed and collaborative Multi-Disciplinary Design Analysis and Optimization (MDAO) environment. The results show a beneficial effect of systems electrification on systems mass and engine specific fuel consumption. At aircraft level, the results point out an increment of aircraft range up to 7.7% with a different trend for the two studied cases.

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