scholarly journals Wave-Rotor-Enhanced Gas Turbine Engines

1997 ◽  
Vol 119 (2) ◽  
pp. 469-477 ◽  
Author(s):  
G. E. Welch ◽  
S. M. Jones ◽  
D. E. Paxson
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Specific Fuel Consumption ◽  
Specific Power ◽  
Inlet Temperature ◽  
Wave Rotor ◽  
Performance Levels ◽  
Turbine Engine ◽  
The Impact

The benefits of wave rotor topping in small (300- to 500-kW [400- to 700-hp] class) and intermediate (2000- to 3000-kw [3000- to 4000-hp] class) turboshaft engines, and large (350- to 450-kN [80,000- to 100,000-lbf] class) high-bypass-ratio turbofan engines are evaluated. Wave rotor performance levels are calculated using a one-dimensional design/analysis code. Baseline and wave-rotor-enhanced engine performance levels are obtained from a cycle deck in which the wave rotor is represented as a burner with pressure gain. Wave rotor topping is shown to enhance the specific fuel consumption and specific power of small- and intermediate-sized turboshaft engines significantly. The specific fuel consumption of the wave-rotor-enhanced large turbofan engine can be reduced while it operates at a significantly reduced turbine inlet temperature. The wave-rotor-enhanced engine is shown to behave off-design like a conventional engine. Discussion concerning the impact of the wave rotor/gas turbine engine integration identifies technical challenges.

scholarly journals Performance Benefits for Wave Rotor-Topped Gas Turbine Engines

1996 ◽  
Author(s):  
Scott M. Jones ◽  
Gerard E. Welch
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Cycle Performance ◽  
Specific Power ◽  
Inlet Temperature ◽  
Wave Rotor ◽  
Turbine Engine ◽  
One Dimensional

The benefits of wave rotor-topping in turboshaft engines, subsonic high-bypass turbofan engines, auxiliary power units, and ground power units are evaluated. The thermodynamic cycle performance is modeled using a one-dimensional steady-state code; wave rotor performance is modeled using one-dimensional design/analysis codes. Design and off-design engine performance is calculated for baseline engines and wave rotor-topped engines, where the wave rotor acts as a high pressure spool. The wave rotor-enhanced engines are shown to have benefits in specific power and specific fuel flow over the baseline engines without increasing turbine inlet temperature. The off-design steady-state behavior of a wave rotor-topped engine is shown to be similar to a conventional engine. Mission studies are performed to quantify aircraft performance benefits for various wave rotor cycle and weight parameters. Gas turbine engine cycles most likely to benefit from wave rotor-topping are identified. Issues of practical integration and the corresponding technical challenges with various engine types are discussed.

scholarly journals A Compact, Intercooled and Regenerated Gas Turbine for HALE Applications

1992 ◽  
Author(s):  
Jennifer J. Kolden ◽  
William J. Bigbee-Hansen ◽  
Donald G. Iverson
Keyword(s):  
Total Energy ◽  
Gas Turbine ◽  
Fuel Consumption ◽  
Optimization Technique ◽  
Specific Fuel Consumption ◽  
Optimization Process ◽  
Turbine Engine ◽  
Installation Effects ◽  
Long Endurance ◽  
The Impact

A mechanically coupled, two spool, intercooled and regenerated gas turbine engine designed for a high altitude, long endurance (HALE) mission is described. The design philosophy was based on minimization of total energy expended using a two stage optimization process utilizing a multivariate regression and optimization technique. This optimization process addressed the impact of the propulsion system as installed on an air vehicle, including all installation effects. Weight and drag of the complete nacelle as they were affected by the characteristics of the engine was included. A brake specific fuel consumption (BSFC) of 0.262 lb/hr/hp (0.159 kg/hr/kw) and mission average specific fuel consumption (MSFC) of 0.266 lb/hp-hr (0.160 kg/kW-hr) was estimated for the bare engine and an MSFC of 0.327 lb/hp-hr (0.199 kg/kW-hr) was estimated for the fully installed engine, including the nacelle drag penalty, where MSFC is defined as the total fuel required to complete the mission divided by the total energy expended during the mission. A comparison with other gas turbine and reciprocating engines currently considered as candidates for HALE applications is also presented.

Measured Effects of Flow Leakage on the Performance of the GT-225 Automotive Gas Turbine Engine

1980 ◽  
Vol 102 (1) ◽  
pp. 14-18 ◽  
Author(s):  
C. C. Matthews
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Performance Data ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Cold Surface ◽  
Turbine Engine ◽  
Turbine Inlet ◽  
Hot Surface

A GT-225 regenerative gas turbine engine was used to obtain engine performance data with varied rates of simulated internal leakage. Regenerator hot surface rim and crossarm seal leaks as well as regenerator cold surface seal leaks were simulated. Instrumentation was included in external ducting to measure the leakage rates. Data were taken at three gasifier turbine speeds with turbine inlet temperature held constant by means of the variable power turbine nozzle and also with varied turbine inlet temperatures resulting from operation with the nozzle fixed at the design area. Component performance data were calculated from the engine measurements to determine the loss mechanisms associated with the leakage. The GT-225 was most sensitive to hot surface rim seal leakage, followed closely by the hot surface crossarm seal leakage, and then the cold surface leakage. Performance was degraded much more when turbine inlet temperature was fixed (by about a factor of three for specific fuel consumption) than for the fixed geometry mode. The effects of leakage became less severe as gasifier turbine speed was increased. The engine performance deterioration due simply to the flow bypass is compounded by induced losses in regenerator and compressor performance leading to very large changes in engine performance, e.g., specific fuel consumption increased up to 80 percent and power decreased as much as 40 percent with 8 percent additional leakage.

Wave-Rotor Pressure-Gain Combustion Analysis for Power Generation and Gas Turbine Applications

2012 ◽  
Author(s):  
Manikanda Rajagopal ◽  
Abdullah Karimi ◽  
Razi Nalim
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Turbulent Flame ◽  
Pressure Rise ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Specific Power ◽  
Inlet Temperature ◽  
Wave Rotor ◽  
Turbine Engine

A wave-rotor pressure-gain combustor (WRPGC) ideally provides constant-volume combustion and enables a gas turbine engine to operate on the Humphrey-Atkinson cycle. It exploits pressure (both compression and expansion) waves and confined propagating combustion to achieve pressure rise inside the combustor. This study first presents thermodynamic cycle analysis to illustrate the improvements of a gas turbine engine possible with a wave rotor combustor. Thereafter, non-steady reacting simulations are used to examine features and characteristics of a combustor rig that reproduces key features of a WRPGC. In the thermodynamic analysis, performance parameters such as thermal efficiency and specific power are estimated for different operating conditions (compressor pressure ratio and turbine inlet temperature). The performance of the WRPGC is compared with the conventional unrecuperated and recuperated engines that operates on the Brayton cycle. Fuel consumption may be reduced substantially with WRPGC introduction, while concomitantly boosting power. Simulations have been performed of the ignition of propane by a hot gas jet and subsequent turbulent flame propagation and shock-flame interaction.

Optimization of Turbofan Propulsion Cycle Using a Genetic Algorithm

2010 ◽  
Author(s):  
Adel Ghenaiet
Keyword(s):  
Genetic Algorithm ◽  
Fuel Consumption ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Optimization Procedure ◽  
Specific Fuel Consumption ◽  
High Mass ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Simplifying Assumptions

This paper presents an evolutionary approach as the optimization framework to design for the optimal performance of a high-bypass unmixed turbofan to match with the power requirements of a commercial aircraft. The parametric analysis had the objective to highlight the effects of the principal design parameters on the propulsive performance in terms of specific fuel consumption and specific thrust. The design optimization procedure based on the genetic algorithm PIKAIA coupled to the developed engine performance analyzer (on-design and off-design) aimed at finding the propulsion cycle parameters minimizing the specific fuel consumption, while meeting the required thrusts in cruise and takeoff and the restrictions of temperatures limits, engine size and weight as well as pollutants emissions. This methodology does not use engine components’ maps and operates on simplifying assumptions which are satisfying the conceptual or early design stages. The predefined requirements and design constraints have resulted in an engine with high mass flow rate, bypass ratio and overall pressure ratio and a moderate turbine inlet temperature. In general, the optimized engine is fairly comparable with available engines of equivalent power range.

Rolls Royce/Allison 501-K Gas Turbine Anti-Fouling Compressor Coatings Evaluation

2002 ◽  
Author(s):  
Daniel E. Caguiat
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Gas Turbines ◽  
Performance Degradation ◽  
Specific Fuel Consumption ◽  
Inlet Temperature ◽  
Test Results ◽  
Turbine Inlet ◽  
Compressor Performance ◽  
Compressor Efficiency

The Naval Surface Warfare Center, Carderock Division (NSWCCD) Gas Turbine Emerging Technologies Code 9334 was tasked by NSWCCD Shipboard Energy Office Code 859 to research and evaluate fouling resistant compressor coatings for Rolls Royce Allison 501-K Series gas turbines. The objective of these tests was to investigate the feasibility of reducing the rate of compressor fouling degradation and associated rate of specific fuel consumption (SFC) increase through the application of anti-fouling coatings. Code 9334 conducted a market investigation and selected coatings that best fit the test objective. The coatings selected were Sermalon for compressor stages 1 and 2 and Sermaflow S4000 for the remaining 12 compressor stages. Both coatings are manufactured by Sermatech International, are intended to substantially decrease blade surface roughness, have inert top layers, and contain an anti-corrosive aluminum-ceramic base coat. Sermalon contains a Polytetrafluoroethylene (PTFE) topcoat, a substance similar to Teflon, for added fouling resistance. Tests were conducted at the Philadelphia Land Based Engineering Site (LBES). Testing was first performed on the existing LBES 501-K17 gas turbine, which had a non-coated compressor. The compressor was then replaced by a coated compressor and the test was repeated. The test plan consisted of injecting a known amount of salt solution into the gas turbine inlet while gathering compressor performance degradation and fuel economy data for 0, 500, 1000, and 1250 KW generator load levels. This method facilitated a direct comparison of compressor degradation trends for the coated and non-coated compressors operating with the same turbine section, thereby reducing the number of variables involved. The collected data for turbine inlet, temperature, compressor efficiency, and fuel consumption were plotted as a percentage of the baseline conditions for each compressor. The results of each plot show a decrease in the rates of compressor degradation and SFC increase for the coated compressor compared to the non-coated compressor. Overall test results show that it is feasible to utilize anti-fouling compressor coatings to reduce the rate of specific fuel consumption increase associated with compressor performance degradation.

The Heat Transfer Performance of Porous Gas Turbine Blades

1968 ◽  
Vol 72 (696) ◽  
pp. 1087-1094 ◽  
Author(s):  
F. J. Bayley ◽  
A. B. Turner
Keyword(s):  
Gas Turbine ◽  
Turbine Blades ◽  
Engine Performance ◽  
Operating Conditions ◽  
Maximum Temperature ◽  
Specific Power ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Turbine Inlet ◽  
Compression And Expansion

It is well known that the performance of the practical gas turbine cycle, in which compression and expansion are non-isentropic, is critically dependent upon the maximum temperature of the working fluid. In engines in which shaft-power is produced the thermal efficiency and the specific power output rise steadily as the turbine inlet temperature is increased. In jet engines, in which the gas turbine has so far found its greatest success, similar advantages of high temperature operation accrue, more particularly as aircraft speeds increase to utilise the higher resultant jet velocities. Even in high by-pass ratio engines, designed specifically to reduce jet efflux velocities for application to lower speed aircraft, overall engine performance responds very favourably to increased turbine inlet temperatures, in which, moreover, these more severe operating conditions apply continuously during flight, and not only at maximum power as with more conventional cycles.

scholarly journals Investigation of Micro Gas Turbine Systems for High Speed Long Loiter Tactical Unmanned Air Systems

Aerospace ◽  
2019 ◽  
Vol 6 (5) ◽  
pp. 55 ◽  
Author(s):  
James Large ◽  
Apostolos Pesyridis
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
High Speed ◽  
Engine Performance ◽  
Operating Conditions ◽  
Turbine Engine ◽  
Micro Gas Turbine ◽  
Fan Speed ◽  
Relative Design ◽  
Design Simplicity

In this study, the on-going research into the improvement of micro-gas turbine propulsion system performance and the suitability for its application as propulsion systems for small tactical UAVs (<600 kg) is investigated. The study is focused around the concept of converting existing micro turbojet engines into turbofans with the use of a continuously variable gearbox, thus maintaining a single spool configuration and relative design simplicity. This is an effort to reduce the initial engine development cost, whilst improving the propulsive performance. The BMT 120 KS micro turbojet engine is selected for the performance evaluation of the conversion process using the gas turbine performance software GasTurb13. The preliminary design of a matched low-pressure compressor (LPC) for the proposed engine is then performed using meanline calculation methods. According to the analysis that is carried out, an improvement in the converted micro gas turbine engine performance, in terms of thrust and specific fuel consumption is achieved. Furthermore, with the introduction of a CVT gearbox, the fan speed operation may be adjusted independently of the core, allowing an increased thrust generation or better fuel consumption. This therefore enables a wider gamut of operating conditions and enhances the performance and scope of the tactical UAV.

Performance and Emission Characteristics of a Small Scale Gas Turbine Engine Fueled With Propanol/Jet A Blends

2011 ◽  
Author(s):  
Carlos J. Mendez ◽  
Ramkumar N. Parthasarathy ◽  
Subramanyam R. Gollahalli
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Gas Turbine Engine ◽  
Single Stage ◽  
Specific Fuel Consumption ◽  
Small Scale ◽  
Emission Characteristics ◽  
Turbine Engine ◽  
Performance And Emission ◽  
Emission Index

Alcohols serve as an alternate energy resource to the conventional petroleum-based fuels. The objective of this study was to document the performance and emission characteristics of blends of n-propanol and Jet A fuel in a small-scale gas turbine engine. The experiments were conducted in a 30kW gas turbine engine with a single-stage centrifugal flow compressor, annular combustion chamber and a single-stage axial flow turbine. In addition to neat propanol and Jet A fuel, three blends, with 25%, 50% and 75% of propanol by volume, were used as the fuels. The thrust, thrust-specific fuel consumption, and the concentrations of CO and NOx in the exhaust were measured and compared with those measured with Jet A fuel. The engine was operated at the same throttle settings with all the fuels. The operational range of engine rotational speed was shifted downwards with the addition of propanol due to its lower heating value. The thrust specific fuel consumption increased with the addition of propanol, while the CO emission index increased and NOx emission index decreased.

Comparative Energy and Exergy Analysis of Proposed Gas Turbine Cycle With Simple Gas Turbine Cycle at Same Operational Cost

2019 ◽  
Author(s):  
M. N. Khan ◽  
Ibrahim M. Alarifi ◽  
I. Tlili
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Exergy Analysis ◽  
Pressure Ratio ◽  
Specific Fuel Consumption ◽  
Exergy Destruction ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Gas Turbine Cycle ◽  
The Impact

Abstract Environmentally friendly and effective power systems have been receiving increased investigation due to the aim of addressing global warming, energy expansion, and economic growth. Gas turbine cycles are perceived as a useful technology that has advanced power capacity. In this research, a gas turbine cycle has been proposed and developed from a simple and regenerative gas turbine cycle to enhance performance and reduce Specific fuel consumption. The impact of specific factors regarding the proposed gas turbine cycle on thermal efficiency, net output, specific fuel consumption, and exergy destruction, have been inspected. The assessments of the pertinent parameters were performed based on conventional thermodynamic energy and exergy analysis. The results obtained indicate that the peak temperature of the Proposed Gas Turbine Cycle increased considerably without affecting fuel consumption. The results show that at Pressure Ratio (rp = 6) the performance of the Proposed Gas Turbine Cycle is much better than Single Gas Turbine Cycle but the total exergy destruction of Proposed Gas Turbine Cycle higher than the SGTC.

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