Large Eddy Simulation of Flow and Convective Heat Transfer in a Gas Turbine Can Combustor With Synthetic Inlet Turbulence

2011 ◽  
Author(s):  
Sunil Patil ◽  
Danesh Tafti
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Convective Heat Transfer ◽  
Gas Turbine ◽  
Convective Heat ◽  
Computational Time ◽  
Computational Domain ◽  
Rans Simulation ◽  
Eddy Simulation ◽  
Large Eddy

Large eddy simulations of swirling flow and the associated convective heat transfer in a gas turbine can combustor under cold flow conditions for Reynolds numbers of 50,000 and 80,000 with characteristic Swirl number of 0.7 are carried out. A precursor Reynolds Averaged Navier-Stokes (RANS) simulation is used to provide the inlet boundary conditions to the large-eddy simulation (LES) computational domain, which includes only the can combustor. A stochastic procedure based on the classical view of the turbulence as superposition of the coherent structures is used to simulate the turbulence at the inlet plane of the computational domain using the mean flow velocity and Reynolds stress data from the precursor RANS simulation. To further reduce the overall computational resource requirement and the total computational time, the near wall region is modeled using zonal two layer model. A novel formulation in generalized co-ordinate system is used for solution of effective tangential velocity and temperature in the inner layer virtual mesh. LES predictions are compared with the experimental data of Patil et al. [1] for the local heat transfer distribution on the combustor liner wall obtained using robust infrared thermography technique. The heat transfer coefficient distribution on the liner wall predicted from LES is in good agreement with experimental values. The location and the magnitude of the peak heat transfer are predicted in very close agreement with the experiments.

Large-Eddy Simulation of Flow and Convective Heat Transfer in a Gas Turbine Can Combustor With Synthetic Inlet Turbulence

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Sunil Patil ◽  
Danesh Tafti
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Convective Heat Transfer ◽  
Gas Turbine ◽  
Convective Heat ◽  
Computational Time ◽  
Computational Domain ◽  
Rans Simulation ◽  
Eddy Simulation ◽  
Large Eddy

Large eddy simulations of swirling flow and the associated convective heat transfer in a gas turbine can combustor under cold flow conditions for Reynolds numbers of 50,000 and 80,000 with a characteristic Swirl number of 0.7 are carried out. A precursor Reynolds averaged Navier-Stokes (RANS) simulation is used to provide the inlet boundary conditions to the large-eddy simulation (LES) computational domain, which includes only the can combustor. A stochastic procedure based on the classical view of turbulence as a superposition of the coherent structures is used to simulate the turbulence at the inlet plane of the computational domain using the mean flow velocity and Reynolds stress data from the precursor RANS simulation. To further reduce the overall computational resource requirement and the total computational time, the near wall region is modeled using a zonal two layer model (WMLES). A novel formulation in the generalized co-ordinate system is used for the solution of effective tangential velocity and temperature in the inner layer virtual mesh. The WMLES predictions are compared with the experimental data of Patil et al. (2011, “Experimental and Numerical Investigation of Convective Heat Transfer in Gas Turbine Can Combustor,” ASME J. Turbomach., 133(1), p. 011028) for the local heat transfer distribution on the combustor liner wall obtained using robust infrared thermography technique. The heat transfer coefficient distribution on the liner wall predicted from the WMLES is in good agreement with experimental values. The location and the magnitude of the peak heat transfer are predicted in very close agreement with the experiments.

scholarly journals Convective heat transfer over a wall mounted cube at different angle of attack using large eddy simulation

2014 ◽  
Vol 18 (suppl.2) ◽  
pp. 301-315
Author(s):  
Habibollah Heidarzadeh ◽  
Mousa Farhadi ◽  
Kurosh Sedighi
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Large Eddy Simulation ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Angle Of Attack ◽  
Scale Model ◽  
Flow Angle ◽  
Eddy Simulation ◽  
Large Eddy

Turbulent fluid flow and convective heat transfer over the wall mounted cube in different flow angle of attack have been studied numerically using Large Eddy Simulation. Cube faces and plate have a constant heat flux. Dynamic Smagorinsky (DS) subgrid scale model were used in this study. Angles were in the range 0???45 and Reynolds number based on the cube height and free stream velocity was 4200. The numerical simulation results were compared with the experimental data of Nakamura et al [6, 7]. Characteristics of fluid flow field and heat transfer compared for four angles of attack. Flow around the cube was classified to four regimes. Results was represented in the form of time averaged normalized streamwise velocity and Reynolds stress in different positions, temperature contours, local and average Nusselt number over the faces of cube. Local convective heat transfer on cube faces was affected by flow pattern around the cube. The local convective heat transfer from the faces of the cube and plate are directly related to the complex phenomena such as horse shoe vortex, arch vortexes in behind the cube, separation and reattachment. Results show that overall convective heat transfer of cube and mean drag coefficient have maximum and minimum value at ?=0 deg and ?=25 deg respectively.

Large Eddy Simulation of Flow and Heat Transfer Mechanism in Matrix Cooling Channel

2017 ◽  
Author(s):  
Yigang Luan ◽  
Lianfeng Yang ◽  
Bo Wan ◽  
Tao Sun
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Transfer Mechanism ◽  
Heat Transfer Mechanism ◽  
Longitudinal Vortices ◽  
Eddy Simulation ◽  
Flow And Heat Transfer ◽  
Large Eddy

Gas turbine engines have been widely used in modern industry especially in the aviation, marine and energy fields. The efficiency of gas turbines directly affects the economy and emissions. It’s acknowledged that the higher turbine inlet temperatures contribute to the overall gas turbine engine efficiency. Since the components are subject to the heat load, the internal cooling technology of turbine blades is of vital importance to ensure the safe and normal operation. This paper is focused on exploring the flow and heat transfer mechanism in matrix cooling channels. In order to analyze the internal flow field characteristics of this cooling configuration at a Reynolds number of 30000 accurately, large eddy simulation method is carried out. Methods of vortex identification and field synergy are employed to study its flow field. Cross-sectional views of velocity in three subchannels at different positions have been presented. The results show that the airflow is strongly disturbed by the bending part. It’s concluded that due to the bending structure, the airflow becomes complex and disordered. When the airflow goes from the inlet to the turning, some small-sized and discontinuous vortices are formed. Behind the bending structure, the size of the vortices becomes big and the vortices fill the subchannels. Because of the structure of latticework, the airflow is affected by each other. Airflow in one subchannel can exert a shear force on another airflow in the opposite subchannel. It’s the force whose direction is the same as the vortex that enhances the longitudinal vortices. And the longitudinal vortices contribute to the energy exchange of the internal airflow and the heat transfer between airflow and walls. Besides, a comparison of the CFD results and the experimental data is made to prove that the numerical simulation methods are reasonable and acceptable.

Gas Turbine Blade Cooling Passage With V and Broken V Shaped Ribs

2016 ◽  
Author(s):  
Sourabh Kumar ◽  
Ryoichi S. Amano
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Heat Extraction ◽  
Design Stage ◽  
Stress Model ◽  
Cfd Simulations ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Cooling Passage

Gas turbine plays a significant role throughout the industrial world. Aircraft propulsion, land-based power generation, and marine propulsion are most notable sectors where gas turbines are extensively used. The power output in these applications can be increased by raising the temperature of the gas entering the turbines. Turbine blades and vanes constrain the temperature of hot gases. For internal cooling design, techniques for heat extraction from the surfaces exposed to hot stream are based on increasing heat transfer areas and the promotion of turbulence of the cooling flow. Heat transfer is enhanced for example due to ribs, bends, rotation and buoyancy effects; all characterizes flow within the channels. Computational Fluid Dynamics (CFD) simulations are carried out using turbulence models like Large Eddy Simulation (LES) and Reynolds stress model (RSM). These CFD simulations were based on advanced computing technology to improve the accuracy of three-dimensional metal temperature prediction that can be applied routinely in the design stage of turbine cooled vanes and blades. The present work is done to study the effect of secondary flow due to the presence of ribs on heat transfer. In this paper, it is obtained by casting repeated continuous V and broken V-shaped ribs on one side of the two passes square channel into the core of blade. Two different combinations of 60° V and Broken 60° V-ribs in the channel are considered. This work is an attempt to collect information about Nusselt number inside the ribbed duct. Large Eddy Simulation (LES) is carried out on the Inlet V and Inverted V outlet continuous and Broken Inlet V and Inverted V-rib arrangements to analyze the flow pattern inside the channel. Hybrid LES/Reynolds Averaged Navier-Strokes (RANS) modeling is used to modify Reynolds stresses using Algebraic Stress Model (ASM), and a CFD strategy is proposed to predict heat transfer across the cooling channel.

scholarly journals Conjugate heat transfer with Large Eddy Simulation for gas turbine components

2009 ◽  
Vol 337 (6-7) ◽  
pp. 550-561 ◽  
Author(s):  
Florent Duchaine ◽  
Simon Mendez ◽  
Franck Nicoud ◽  
Alban Corpron ◽  
Vincent Moureau ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Eddy Simulation ◽  
Large Eddy

LES Investigation of Modified Rib Shapes on Heat Transfer in a Ribbed Duct

2021 ◽  
Author(s):  
K Sreekesh ◽  
Danesh K. Tafti ◽  
S Vengadesan
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Flow Direction ◽  
Internal Cooling ◽  
Square Duct ◽  
Flow Losses ◽  
Heat Transfer Augmentation ◽  
Eddy Simulation ◽  
Large Eddy

Abstract Internal cooling of gas turbine blade is critical for the durability of the blade material. One of the ways to accomplish this is by passing coolant through serpentine passages roughened with surface elements to enhance the heat transfer. In the present study, the traditional square rib (SQ-rib) placed normal to the flow direction is modified to a backward facing step rib (BS-rib) and a forward facing step rib (FS-rib). Large-eddy simulation (LES) is carried out for a square duct at Reb = 20000. Results show that the modified rib shapes result in substantial increase in heat transfer over the square rib with only a marginal increase in flow losses. The BS-rib shape produces the highest heat transfer augmentation followed by the FS-rib. The overall heat transfer augmentation for the BS-rib and FS-rib is 18% and 10% larger than the SQ-rib, respectively. Thermal-hydraulic performance is enhanced by 15%.

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