Redesign of a Centrifugal Compressor’s Vaned Diffuser to Improve Core Engine Performances

2006 ◽  
Author(s):  
Victor I. Mileshin ◽  
Andrew N. Startsev ◽  
Igor A. Brailko ◽  
Igor K. Orekhov
Keyword(s):  
Flow Rate ◽  
Total Pressure ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Vaned Diffuser ◽  
Exhaust Temperature ◽  
Turbine Inlet ◽  
Total Pressure Ratio ◽  
Turbine Exhaust

Present paper is devoted to numerical optimization of a 8:1 total pressure ratio centrifugal compressor to improve performances of core engine belonging to a turbo-shaft engine. Main subject of optimization is vaned diffuser with following impeller’s pressure ratio increase. This compressor designed by CIAM [7] and tested as a part of core engine gave satisfactory performances even under the first test run. Further development requires new concepts one of which is reduction of core engine’s turbine inlet temperature. Redesign of vaned diffuser through elimination of reverse flow zone gives 5% increase of mass flow-rate and 0.7% increase of efficiency. Further 6% increase of impeller’s total pressure ratio (at the same rpm) modifies Brayton cycle of core engine reducing turbine inlet temperature by 32° and turbine exhaust temperature by 43°. To maintain the same power output, this drop of turbine exhaust temperature is compensated by 4% increase of the operational flow-rate.

Proposal of Innovative Gas Turbine Combined Cycle Power Generation System

2004 ◽  
Author(s):  
Hideto Moritsuka
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Generation System ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Power Generation System

In order to estimate the possibility to improve thermal efficiency of power generation use gas turbine combined cycle power generation system, benefits of employing the advanced gas turbine technologies proposed here have been made clear based on the recently developed 1500C-class steam cooling gas turbine and 1300C-class reheat cycle gas turbine combined cycle power generation systems. In addition, methane reforming cooling method and NO reducing catalytic reheater are proposed. Based on these findings, the Maximized efficiency Optimized Reheat cycle Innovative Gas Turbine Combined cycle (MORITC) Power Generation System with the most effective combination of advanced technologies and the new devices have been proposed. In case of the proposed reheat cycle gas turbine with pressure ratio being 55, the high pressure turbine inlet temperature being 1700C, the low pressure turbine inlet temperature being 800C, combined with the ultra super critical pressure, double reheat type heat recovery Rankine cycle, the thermal efficiency of combined cycle are expected approximately 66.7% (LHV, generator end).

Analyses and Optimization of a Propulsion Cycle for Unmixed High Bypass Turbofan

2008 ◽  
Author(s):  
Adel Ghenaiet
Keyword(s):  
Fuel Consumption ◽  
Pressure Ratio ◽  
Specific Fuel Consumption ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
High Pressure Ratio ◽  
Turbine Inlet ◽  
Design Variables ◽  
Bypass Ratio

This paper deals with a parametric study and an optimization for the design variables of a high bypass unmixed turbofan equipping commercial aircrafts. The objective of the first part of this study is to highlight the effects of the principal design parameters (bypass ratio, compression ratios, turbine inlet temperature etc..) on the uninstalled performance, in terms of specific thrust and specific fuel consumption. The second part concerns the optimization, aiming at finding the optimum design parameters concurrently minimizing the specific fuel consumption at cruise, and meeting the thrust requirement at takeoff. The cycle analyzer (on-design and off-design) as coupled to the optimization algorithm MMFD by adopting a random multi-starts search strategy is shown to be stable and converging. The predefined requirements and constraints have dictated utilizing an engine with a high-bypass ratio, high-pressure ratio and a moderate turbine inlet temperature. In general, the obtained results compare fairly well with typical data available for an equivalent ‘reference’ engine. This elaborated methodology is shown to be consistent with the conceptual design requirements and accuracy, because, it does not use components’ characteristics, and operates on simplifying assumptions. This present methodology can be readily adapted for other configurations of aero-engines as well, and easily integrated in a multi-disciplinary design approach.

Conjugate Flow and Heat Transfer Investigation of a Turbo Charger: Part II — Experimental Results

2003 ◽  
Author(s):  
Dieter Bohn ◽  
Norbert Moritz ◽  
Michael Wolff
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Inlet Temperature ◽  
Total Heat Flux ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Turbo Charger

In this paper the results of experimental investigations are presented that were performed at the institute’s turbo charger test stand to determine the heat flux between the turbine and the compressor of a passenger car turbo charger. A parametric study has been performed varying the turbine inlet temperature and the mass flow rate. The aim of the analysis is to provide a relation of the Reynolds number at the compressor inlet and the heat flux from the turbine to the compressor with the turbine inlet temperature as the parameter. Thereto, the analysis of the local heat fluxes is necessary which is performed in a numerical conjugate heat transfer and flow analysis which is presented in part I of the paper. Beyond the measurements necessary to determine the operating point of compressor and turbine, the surface temperature of the casings were measured by resistance thermometers at different positions and by thermography. All measurement results were used as boundary conditions for the numerical simulation, i.e. the inlet and outlet flow conditions for compressor and turbine, the rotational speed, the oil temperatures and the temperature distribution on the outer casing surface of the turbo charger. The experimental results show that the total heat flux from turbine to compressor is mainly influenced by the turbine inlet temperature. The increase of the mass flow rate leads to a higher pressure ratio in the compressor so that the compressor casing temperature is increased. Due to the turbo charger’s geometry heat radiation has a small influence on the total heat flux.

A 2000-HP Military Vehicle Gas Turbine: A Study of Significant Thermodynamic and Mechanical Parameters

1968 ◽  
Author(s):  
A. F. Carter
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Overall Design ◽  
Blade Cooling ◽  
Turbine Inlet ◽  
Military Vehicle ◽  
Compressor Pressure Ratio ◽  
Selection Of

During a study of possible gas turbine cycles for a 2000-hp unit for tank propulsion, it has been established that the level of achievable specific fuel consumption (sfc) is principally determined by the combustor inlet temperature. If a regenerative cycle is selected, a particular value of combustor inlet temperature (and hence sfc) can be produced by an extremely large number of combinations of compressor pressure ratio, turbine inlet temperature, and heat exchanger effectiveness. This paper outlines the overall design considerations which led to the selection of a relatively low pressure ratio engine in which the turbine inlet temperature was sufficiently low that blade cooling was not necessary.

Comparative Thermodynamic Analysis of Gas Turbine Systems with Turbine Blade Film Cooling

2012 ◽  
Vol 505 ◽  
pp. 539-543
Author(s):  
Kyoung Hoon Kim ◽  
Kyoung Jin Kim ◽  
Chul Ho Han
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Thermodynamic Analysis ◽  
Film Cooling ◽  
Pressure Ratio ◽  
Turbine Blades ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Blade Cooling ◽  
Turbine Inlet

Since the gas turbine systems require active cooling to maintain high operating temperature while avoiding a reduction in the system operating life, turbine blade cooling is very important and essential but it may cause the performance losses in gas turbine. This paper deals with the comparative thermodynamic analysis of gas turbine system with and without regeneration by using the recently developed blade-cooling model when the turbine blades are cooled by the method of film cooling. Special attention is paid to investigating the effects of system parameters such as pressure ratio and turbine inlet temperature on the thermodynamic performance of the systems. In both systems the thermal efficiency increases with turbine inlet temperature, but its effect is less sensitive in simpler system

Exergy Analysis of an Indirectly-Fired Combined Cycle Power Generation System

2008 ◽  
Author(s):  
Kin F. Chui ◽  
Nirmal V. Gnanapragasam ◽  
Bale V. Reddy ◽  
Ramesh C. Prasad
Keyword(s):  
Natural Gas ◽  
Circulating Fluidized Bed ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Firing Mode ◽  
Fluidized Bed Combustor

A natural gas fired combined cycle power plant with indirectly-fired heating for additional work output is investigated in the current work. The mass flow rate of coal for the indirect firing mode in circulating fluidized bed combustor is estimated based on fixed natural gas input to the topping combustor. The effects of pressure ratio, gas turbine inlet temperature, inlet temperature to the topping combustor on the exergetic performance of the combined cycle configuration are analysed. The use of coal in indirect-firing mode reduces with increase in turbine inlet temperature due to increase in the use of natural gas. The exergetic efficiency increases with pressure ratio up to the optimum pressure and it also increase with gas turbine inlet temperature. The exergy destruction is highest for the circulating fluidized bed combustor (CFBC) followed by the topping combustor. The analyses show that the indirectly fired mode of the combined cycle offers better performance but with higher exergy destruction and the opportunity for additional net work output by using solid fuels (coal in this case) in existing natural gas based power plant is realized.

scholarly journals Exergy, economic and environmental (3E) analysis of a gas turbine power plant and optimization by MOPSO algorithm

2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2641-2651 ◽  
Author(s):  
Moein Shamoushaki ◽  
Mehdi Ehyaei
Keyword(s):  
Gas Turbine ◽  
Co2 Emission ◽  
Emission Rate ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Total Cost ◽  
Cost Rate ◽  
Turbine Inlet ◽  
Compressor Pressure Ratio

In this paper, exergy, exergoeconomic, and exergoenvironmental analysis of a gas turbine cycle and its optimization has been carried out by MOPSO algorithm. Three objective functions, namely, total cost rate, exergy efficiency of cycle, and CO2 emission rate have been considered. The design variables considered are: compressor pressure ratio, combustion chamber inlet temperature, gas turbine inlet temperature, compressor, and gas turbine isentropic efficiency. The impact of change in gas turbine inlet temperature and compressor pressure ratio on CO2 emission rate as well as impact of changes in gas turbine inlet temperature on exergy efficiency of the cycle has been investigated in different compressor pressure ratios. The results showed that with increase in compressor pressure ratio and gas turbine inlet temperature, CO2 emission rate decreases, that is this reduction is carried out with a steeper slope at lower pressure compressor ratio and gas turbine inlet temperature. The results showed that exergy efficiency of the cycle increases with increase in gas turbine inlet temperature and compressor pressure ratio. The sensitivity analysis of fuel cost changes was performed on objective functions. The results showed that at higher exergy efficiencies total cost rate is greater, and sensitivity of fuel cost optimum solutions is greater than Pareto curve with lower total cost rate. Also, the results showed that sensitivity of changes in fuel cost rate per unit of energy on total cost rate is greater than the rate of CO2 emission.

Introduction of Intercooling in a High Bypass Jet Engine

2000 ◽  
Author(s):  
Tilemachos Papadopoulos ◽  
Pericles Pilidis
Keyword(s):  
Heat Pipe ◽  
Pressure Ratio ◽  
Preliminary Investigation ◽  
Propulsion System ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Jet Engine ◽  
Turbine Inlet ◽  
Weight Penalty ◽  
Bypass Ratio

In this paper an exercise to introduce intercooling in a high bypass civil turbofan is outlined. The engine selected as the basic propulsion system is a three spool high bypass turbofan with a bypass ratio 6.4. The air leaving the IP compressor is cooled in the bypass duct prior to entering the HP compressor. This preliminary investigation appears to indicate that the main benefit to be gained is an increase in the net thrust from the engine without increasing the turbine inlet temperature. To keep engine diameter constant, the bypass ratio has not been changed. This results in a requirement to significantly increase the pressure ratio to reduce the SFC levels to an acceptable value. A sizing exercise has been carried out to understand the weight and volume penalties imposed by heat pipe intercooling hardware. The preliminary sizing exercise indicates that the weight penalty is very large. The performance of the aircraft using the intercooled engines is also investigated and some improvements in performance are predicted. Overall this investigation is considered to be positive so that further investigations should be considered. It appears that an intercooled engine can produce a somewhat higher thrust at a given turbine entry temperature at similar SFC levels of current engines, or, if a small increase in SFC is acceptable, the increase in thrust is quite important.

Performance Analysis of a 50KW Turbogenerator Gas Turbine Engine

1998 ◽  
Author(s):  
S. Y. Kim ◽  
M. R. Park ◽  
S. Y. Cho
Keyword(s):  
Performance Analysis ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Hybrid Vehicle ◽  
Gas Turbine Engine ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Turbine Engine ◽  
Design Point ◽  
Turbine Inlet

This paper describes on/off design performance of a 50KW turbogenerator gas turbine engine for hybrid vehicle application. For optimum design point selection, a relevant pa4rameter study is carried out. The turbogenerator gas turbine engine for a hybrid vehicle is expected to be designed for maximum fuel economy, ultra low emissions, and very low cost. A compressor, combustor, turbine, and a permanent-magnet generator will be mounted on a single high speed (80,000 rpm) shaft that will be supported on air bearings. As the generator is built into the shaft, gearbox and other moving parts become unnecessary and thus will increase the system’s reliability and reduce the manufacturing cost. The engine has a radial compressor and turbine with design point pressure ratio of 4.0. This pressure ratio was set based on calculation of specific fuel consumption and specific power variation with pressure ratio. For the turbine inlet temperature, a rather conservative value of 1100K was selected. Designed mass flow rate was 0.5 kg/sec. Parametric study of the cycle indicates that specific work and efficiency increase at a given pressure ratio and turbine inlet temperature. Off design analysis shows that the gas turbine system reaches self operating condition at about N/NDP = 0.48. Bleeding air for a turbine stator cooling is omitted considering the low TIT in the present engine and to enable the simple geometric configuration for manufacturing purpose. Various engine performance simulations including ambient temperature influence, surging at part load condition; transient analysis were performed to secure the optimum engine operating characteristics. Surge margin throughout the performance analysis were maintained to be over 50% approximately. Present analysis will be compared with performance test result which is scheduled at the end of 1998.

Investigation of Effects of Radial Distortion on Transonic Fan Behavior

2010 ◽  
Author(s):  
Dmytro M. Voytovych ◽  
Guoping Xia ◽  
Chenzhou Lian ◽  
Charles L. Merkle
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Total Pressure ◽  
Pressure Ratio ◽  
Tip Vortex ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Transonic Fan ◽  
Total Pressure Ratio

The flow analysis around blades of a transonic fan is presented for both clean and radially distorted inlets. Computations are shown for four-blade passages that are accomplished with a second order accurate code using a k-ω turbulence model. The mass flow rate along a speed line is controlled by varying a choked nozzle downstream of the fan. The results show good agreement with data for three speed lines. In the near-stall region, the flow first becomes unsteady and then unstable with the unsteadiness increasing at lower speeds. The four-blade simulations remained stable to lower mass flow rates than the single-blade simulations. In the near-stall vicinity, tip vortex breakdown occurred creating a low momentum zone near the blade tip on the pressure side that grew as the mass flow was decreased until it eventually blocked the passage. The presence of distortion reduced the operational range and moved the stall line to higher mass flow rates. At high speeds distortion reduced both the mass flow rate and total pressure ratio while at lower speeds, the choking mass flow rate was reduced, but the total pressure ratio was slightly improved. The flow separation near the hub on the suction side was caused by the distortion. Its size was decreasing with rotational speed.

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