COMPUTATIONAL INVESTIGATION OF THE FLOW IN PRE-SWIRL STATOR-ROTOR SYSTEMS

2004 ◽  
Vol 01 (02) ◽  
pp. 329-343
Author(s):  
A. C. BENIM ◽  
D. BRILLERT ◽  
M. CAGAN
Keyword(s):  
Gas Turbine ◽  
Validation Studies ◽  
Computational Analysis ◽  
Direct Transfer ◽  
Computational Investigation ◽  
Rotor Systems ◽  
Turbine Cooling ◽  
Gas Turbine Cooling ◽  
Computational Procedures

A 3D computational analysis has been applied to investigate direct transfer, pre-swirl systems for gas turbine cooling. Alternative computational procedures have been applied and results have been compared with measurements. Based on these validation studies, strategies for modeling such systems have been proposed. Present results suggest that sufficiently accurate predictions can be obtained using a quasi-steady analysis applying the "frozen rotor" approach for treating the interface between the stationary and rotating domains.

Investigation Into the Computational Analysis of Direct-Transfer Pre-Swirl Systems for Gas Turbine Cooling

2004 ◽  
Author(s):  
A. C. Benim ◽  
D. Brillert ◽  
M. Cagan
Keyword(s):  
Gas Turbine ◽  
Relative Position ◽  
Validation Studies ◽  
Computational Analysis ◽  
Direct Transfer ◽  
Computational Approaches ◽  
Turbine Cooling ◽  
Dimensionless Pressure ◽  
Gas Turbine Cooling

Direct transfer pre-swirl systems have been investigated by means of 3D computational analysis. Different computational approaches have been utilized and results have been compared with measurements. Based on the validation studies, guidelines for modeling such systems have been proposed. The present results imply that sufficiently accurate predictions can be obtained by means of a quasi-steady analysis applying the “frozen rotor” approach for treating the interface between the stationary and rotating domains. The results indicate that the dimensionless pressure and temperature show a rather weak sensitivity to the relative position of the stator and rotor, using the frozen rotor approach, for the cases studied.

scholarly journals Two-Stage Evaporative Inlet Air Gas Turbine Cooling

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1382
Author(s):  
Obida Zeitoun
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Evaporative Cooling ◽  
Air Cooling ◽  
Vapor Compression ◽  
Two Stage ◽  
Turbine Cooling ◽  
Riyadh City ◽  
Vapor Compression Refrigeration ◽  
Gas Turbine Cooling

Gas turbine inlet air-cooling (TIAC) is an established technology for augmenting gas turbine output and efficiency, especially in hot regions. TIAC using evaporative cooling is suitable for hot, dry regions; however, the cooling is limited by the ambient wet-bulb temperature. This study investigates two-stage evaporative TIAC under the harsh weather of Riyadh city. The two-stage evaporative TIAC system consists of indirect and direct evaporative stages. In the indirect stage, air is precooled using water cooled in a cooling tower. In the direct stage, adiabatic saturation cools the air. This investigation was conducted for the GE 7001EA gas turbine model. Thermoflex software was used to simulate the GE 7001EA gas turbine using different TIAC systems including evaporative, two-stage evaporative, hybrid absorption refrigeration evaporative and hybrid vapor-compression refrigeration evaporative cooling systems. Comparisons of different performance parameters of gas turbines were conducted. The added annual profit and payback period were estimated for different TIAC systems.

Build Direction Effects on Additively Manufactured Channels

2015 ◽  
Author(s):  
Jacob C. Snyder ◽  
Curtis K. Stimpson ◽  
Karen A. Thole ◽  
Dominic Mongillo
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Small Scale ◽  
Turbine Cooling ◽  
Gas Turbine Cooling ◽  
Gas Turbine Heat Transfer ◽  
Manufacturing Techniques ◽  
Traditional Manufacturing

With the advances of Direct Metal Laser Sintering (DMLS), also generically referred to as additive manufacturing, novel geometric features of internal channels for gas turbine cooling can be achieved beyond those features using traditional manufacturing techniques. There are many variables, however, in the DMLS process that affect the final quality of the part. Of most interest to gas turbine heat transfer designers are the roughness levels and tolerance levels that can be held for the internal channels. This study investigates the effect of DMLS build direction and channel shape on the pressure loss and heat transfer measurements of small scale channels. Results indicate that differences in pressure loss occur between the test cases with differing channel shapes and build directions, while little change is measured in heat transfer performance.

Scaling Heat-Transfer Coefficients Measured Under Laboratory Conditions to Engine Conditions

2017 ◽  
Author(s):  
T. I.-P. Shih ◽  
C.-S. Lee ◽  
K. M. Bryden
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Gas Turbine ◽  
Scaling Factor ◽  
Rate Of Change ◽  
Transfer Enhancement ◽  
Scaling Factors ◽  
Turbine Cooling ◽  
Pin Fins ◽  
Gas Turbine Cooling

Almost all measurements of the heat-transfer coefficient (HTC) or Nusselt number (Nu) in gas-turbine cooling passages with heat-transfer enhancement features such as pin fins and ribs have been made under conditions, where the wall-to-bulk temperature, Tw/Tb, is near unity. Since Tw/Tb in gas-turbine cooling passages can be as high as 2.2 and vary appreciably along the passage, this study examines if it is necessary to match the rate of change in Tw/Tb when measuring Nu, whether Nu measured at Tw/Tb near unity needs to be scaled before used in design and analysis of turbine cooling, and could that scaling for ducts with heat-transfer enhancement features be obtained from scaling factors for smooth ducts because those scaling factors exist in the literature. In this study, a review of the data in the literature shows that it is unnecessary to match the rate of change in Tw/Tb for smooth ducts at least for the rates that occur in gas turbines. For ducts with heat-transfer enhancement features, it is still an open question. This study also shows Nu measured at Tw/Tb near unity needs to be scale to the correct Tw/Tb before it can be used for engine conditions. By using steady RANS analysis of the flow and heat transfer in a cooling channel with a staggered array of pin fins, the usefulness of the scaling factor, (Tw/Tb)r, from the literature for smooth ducts was examined. Nuengine, computed under engine conditions, was compared with those computed under laboratory conditions, Nulab, and scaled by (Tw/Tb)r; i.e., Nulab,scaled = Nulab (Tw/Tb)r. Results obtained show the error in Nulab,scaled relative to Nuengine can be as high as 36.6% if r = −0.7 and Tw/Tb = 1.573 in the “fully” developed region. Thus, (Tw/Tb)r based on smooth duct should not be used as a scaling factor for Nu in cooling passages with heat-transfer enhancement features. To address this inadequacy, a method is proposed for generating scaling factors, and a scaling factor was developed to scale the heat transfer from laboratory to engine conditions for a channel with pin fins.

Two-Phase Transpiration Cooling

1982 ◽  
Author(s):  
M. A. El-Masri
Keyword(s):  
Gas Turbine ◽  
Transpiration Cooling ◽  
System Behavior ◽  
Two Phase ◽  
Modes Of Operation ◽  
Considerable Potential ◽  
Closed Form Solutions ◽  
Turbine Cooling ◽  
Gas Turbine Cooling ◽  
Hot Surface

Two-phase transpiration is shown to possess considerable potential for gas turbine cooling. In this concept, water fed into a porous component boils within the wall. The resulting steam issues from the hot surface forming the transpiration film. A model for the performance of such a system is developed. Assuming constant properties and a linear reduction of Stanton number with transpiration rate, closed-form solutions are obtained. The governing dimensionless parameters are identified, the system behavior predicted, and the modes of operation delineated. Those are defined as two-phase, partially-flooded, and completely-flooded modes. At low values of a certain “modified Peclet number,” the two-phase mode is unstable and the system tends to flood. Large values of this parameter indicate stable, well-regulated behavior. Discussions on gas turbine applications are presented. A typical numerical example is given in the Appendix.

Two-Phase Transpiration Cooling

1983 ◽  
Vol 105 (1) ◽  
pp. 106-113
Author(s):  
M. A. El-Masri
Keyword(s):  
Gas Turbine ◽  
Transpiration Cooling ◽  
System Behavior ◽  
Two Phase ◽  
Modes Of Operation ◽  
Considerable Potential ◽  
Closed Form Solutions ◽  
Turbine Cooling ◽  
Gas Turbine Cooling ◽  
Hot Surface

Two-phase transpiration is shown to possess considerable potential for gas turbine cooling. In this concept, water fed into a porous component boils within the wall. The resulting steam issues from the hot surface forming the transpiration film. A model for the performance of such a system is developed. Assuming constant properties and a linear reduction of Stanton number with transpiration rate, closed-form solutions are obtained. The governing dimensionless parameters are identified, the system behavior predicted, and the modes of operation delineated. Those are defined as two-phase, partially-flooded, and completely-flooded modes. At low values of a certain “modified Peclet number,” the two-phase mode is unstable and the system tends to flood. Large values of this parameter indicate stable, well-regulated behavior. Discussions on gas turbine applications are presented. A typical numerical example is given in the Appendix.

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