Flow and Heat Transfer Characteristics in a Gas Turbine Can Combustor

2015 ◽  
Author(s):  
Saad A. Mohammed ◽  
Essam E. Khalil ◽  
Hatem Kayed
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Gas Turbine ◽  
Swirling Flow ◽  
Heat Transfer Characteristics ◽  
Swirl Number ◽  
Number Range ◽  
Heat Transfer Augmentation ◽  
Transfer Characteristics ◽  
Peak Location

This paper presents a numerical computations are performed to investigate the convective heat transfer characteristics of a gas turbine can combustor under cold flow conditions in a Reynolds number range between 50,000 and 600,000 with a characteristic swirl number of 0.7. The RNG (K-ε Model) predictions are compared with the experimental data of local heat transfer distribution on the combustor liner wall. It was observed that the flow field in the combustor is characterized by an expanding swirling flow, which impinges on the liner wall close to the inlet of the combustor. The impinging shear layer is responsible for the peak location of heat transfer augmentation. It is observed that as Reynolds number increases, the peak heat transfer augmentation ratio (compared with fully developed pipe flow) reduces from 10.5 to 2.7. Additionally, the peak location does not change with Reynolds number since the flow structure in the combustor is also a function of the swirl number. The heat transfer coefficient distribution on the liner wall predicted from the RNG (K-ε Model) 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.

Experimental and Numerical Investigation of Convective Heat Transfer in a Gas Turbine Can Combustor

2009 ◽  
Author(s):  
Sunil Patil ◽  
Santosh Abraham ◽  
Danesh Tafti ◽  
Srinath Ekkad ◽  
Yong Kim ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Shear Layer ◽  
Convective Heat Transfer ◽  
Gas Turbine ◽  
Convective Heat ◽  
Swirl Number ◽  
Number Range ◽  
Heat Transfer Augmentation ◽  
Peak Location

Experiments and numerical computations are performed to investigate the convective heat transfer characteristics of a gas turbine can combustor under cold flow conditions in a Reynolds number range between 50,000 and 500,000 with a characteristic swirl number of 0.7. It is observed that the flow field in the combustor is characterized by an expanding swirling flow which impinges on the liner wall close to the inlet of the combustor. The impinging shear layer is responsible for the peak location of heat transfer augmentation. It is observed that as Reynolds number increases from 50,000 to 500,000, the peak heat transfer augmentation ratio (compared to fully-developed pipe flow) reduces from 10.5 to 2.75. This is attributed to the reduction in normalized turbulent kinetic energy in the impinging shear layer which is strongly dependent on the swirl number that remains constant at 0.7 with Reynolds number. Additionally, the peak location does not change with Reynolds number since the flow structure in the combustor is also a function of the swirl number. The size of the corner recirculation zone near the combustor liner remains the same for all Reynolds numbers and hence the location of shear layer impingement and peak augmentation does not change.

Experimental and Numerical Investigation of Convective Heat Transfer in a Gas Turbine Can Combustor

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Sunil Patil ◽  
Santosh Abraham ◽  
Danesh Tafti ◽  
Srinath Ekkad ◽  
Yong Kim ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Shear Layer ◽  
Convective Heat Transfer ◽  
Gas Turbine ◽  
Convective Heat ◽  
Swirl Number ◽  
Number Range ◽  
Heat Transfer Augmentation ◽  
Peak Location

Experiments and numerical computations are performed to investigate the convective heat transfer characteristics of a gas turbine can combustor under cold flow conditions in a Reynolds number range between 50,000 and 500,000 with a characteristic swirl number of 0.7. It is observed that the flow field in the combustor is characterized by an expanding swirling flow, which impinges on the liner wall close to the inlet of the combustor. The impinging shear layer is responsible for the peak location of heat transfer augmentation. It is observed that as Reynolds number increases from 50,000 to 500,000, the peak heat transfer augmentation ratio (compared with fully developed pipe flow) reduces from 10.5 to 2.75. This is attributed to the reduction in normalized turbulent kinetic energy in the impinging shear layer, which is strongly dependent on the swirl number that remains constant at 0.7 with Reynolds number. Additionally, the peak location does not change with Reynolds number since the flow structure in the combustor is also a function of the swirl number. The size of the corner recirculation zone near the combustor liner remains the same for all Reynolds numbers and hence the location of shear layer impingement and peak augmentation does not change.

scholarly journals Flow Regimes and Heat Transfer Characteristics in Combustion Chambers

2015 ◽  
Vol 12 (2) ◽  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Swirling Flow ◽  
Local Heat Transfer ◽  
Reacting Flow ◽  
Heat Transfer Characteristics ◽  
Swirl Number ◽  
Number Range ◽  
Transfer Characteristics ◽  
Combustor Liner

This paper presents a numerical computations are performed to investigate the convective heat transfer characteristics of a gas turbine can combustor under non reacting flow conditions in a Reynolds number range 50,000 to 600,000 with a characteristic swirl number of 0.7. A sample of computational predictions of flow behaviors under reacting conditions are also shown for swirling furnace flow of 0.52. The RNG (K-ɛ Model) predictions are compared with the experimental data of local heat transfer distribution on the combustor liner wall. It was observed that the flow field in the combustor is characterized by an expanding swirling flow, which impinges on the liner wall close to the inlet of the combustor. The peak heat transfer augmentation ratio (compared with fully developed pipe flow) reduces from 10.5 to 2.7. Additionally, the peak location does not change with Reynolds number since the flow structure in the combustor is also a function of the swirl number. The size of the corner recirculation zone near the combustor liner remains the same for all Reynolds numbers and hence the location of shear layer impingement and peak augmentation does not change. The heat transfer coefficient distribution on the liner wall predicted from the RNG (K-ɛ Model) 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.

Study of Flow and Convective Heat Transfer in a Simulated Scaled Up Low Emission Annular Combustor

2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Sunil Patil ◽  
Teddy Sedalor ◽  
Danesh Tafti ◽  
Srinath Ekkad ◽  
Yong Kim ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Convective Heat ◽  
Swirling Flow ◽  
Numerical Study ◽  
Swirl Number ◽  
Maximum Heat ◽  
Number Range ◽  
Maximum Heat Transfer ◽  
Annular Combustor

Modern dry low emissions (DLE) combustors are characterized by highly swirling and expanding flows that makes the convective heat load on the gas side difficult to predict and estimate. A coupled experimental–numerical study of swirling flow inside a DLE annular combustor model is used to determine the distribution of heat transfer on the liner walls. Three different Reynolds numbers are investigated in the range of 210,000–840,000 with a characteristic swirl number of 0.98. The maximum heat transfer coefficient enhancement ratio decreased from 6 to 3.6 as the flow Reynolds number increased from 210,000 to 840,000. This is attributed to a reduction in the normalized turbulent kinetic energy in the impinging shear layer, which is strongly dependent on the swirl number that remains constant at 0.98 for the Reynolds number range investigated. The location of peak heat transfer did not change with the increase in Reynolds number since the flow structures in the combustors did not change with Reynolds number. Results also showed that the heat transfer distributions in the annulus have slightly different characteristics for the concave and convex walls. A modified swirl number accounting for the step expansion ratio is defined to facilitate comparison between the heat transfer characteristics in the annular combustor with previous work in a can combustor. A higher modified swirl number in the annular combustor resulted in higher heat transfer augmentation and a slower decay with Reynolds number.

Heat Transfer Characteristics of Low Reynolds Number Turbulent Swirling LPG/Air Flame Impinging on a Flat Surface

2010 ◽  
Author(s):  
Arun Kaushal ◽  
Gurpreet Singh ◽  
Subhash Chander ◽  
Anjan Ray
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Flat Surface ◽  
Low Reynolds Number ◽  
Reynolds Numbers ◽  
Heat Transfer Characteristics ◽  
Swirl Number ◽  
Transfer Characteristics ◽  
Swirling Flames ◽  
Low Reynolds

An experimental study has been conducted to determine the heat transfer characteristics for low Reynolds number turbulent swirling LPG/Air flames impinging on a flat surface. Effect of variation of Reynolds number (3000–7000), dimensionless separation distance (H/d = 1 to 6) and equivalence ratio (φ = 0.8 to 2) on heat transfer characteristics has been determined at constant swirl number of 4. Further, experiments were also conducted to investigate the effect of swirl number on heat transfer characteristics at Re = 7000, φ = 1.0 and H/d = 5. It has been concluded that the major drawback of flame impingement i.e., non-uniformity in the heating can be resolved by using swirling flames in place of non-swirling flames. With increase in Reynolds number the flame becomes longer and broader. Also, at higher Re the flame becomes noisy and violent because of the enhanced turbulences in the flame. A dip in the temperature was observed at the stagnation point at all Re and this dip was more significant at higher Re. At small separation distances (H/d = 1 and 2) and at large Reynolds numbers (Re = 7000) heating is comparatively more non-uniform because of close proximity of the visible reaction zone to the plate resulting in intense heating in the stagnation region. High average heat fluxes were obtained at low separation distances and at larger Reynolds numbers.

Flow and Heat Transfer Characteristics in a Channel Periodically Fitted with Blocks and Inclined Plates

2011 ◽  
Vol 66-68 ◽  
pp. 299-306
Author(s):  
Jian Sheng Wang ◽  
Cui Wu
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
The Self ◽  
Sustained Oscillation ◽  
Heat Transfer Characteristics ◽  
Number Range ◽  
Transfer Characteristics ◽  
Plate Length ◽  
Cfd Method ◽  
Inclined Plates

A numerical investigation in the CFD method of the heat transfer characteristics and the self-sustained oscillation flow is conducted in a grooved channel with periodic mounted inclined plate.Control of low Reynolds number range(600-1600), two-dimensional, unsteady laminar flow was analyzed .Various physical and flow arrangements have been considered as plate length, plate position and Reynolds number .A comparison among different channels was made for streamlines、history of cartesian velocity component in the x-direction and Nusselt number(Nu)．Compared with the results got by the no plates case, the heat transfer has been enhanced in channel that installation of a inlined plate for all Reynolds number.At higher Reynolds number(Reynolds number over the critical Reynolds number), the enhancement of heat transfer is more marked ,that because it can not only modify the direction of the flow towards the obstacle faces to be cooled ,and activate the self-oscillations using inclined plates placed periodically.

The Experimental Study on Fluid Heat Transfer Characteristics in Narrow Annuli

2011 ◽  
Vol 422 ◽  
pp. 762-766
Author(s):  
Shao Feng Yan ◽  
Xiu Juan Bian ◽  
Bo Yuan Sui
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Cold Water ◽  
Hot Water ◽  
Strengthening Effect ◽  
Heat Transfer Characteristics ◽  
Number Range ◽  
Transfer Characteristics

Heat exchanger of Sleeve type was used in the experiment with water for working medium, hot water inside of tube, cold water outside of tube, For ring gap of 0.50mm~2.50mm, Reynolds number range in 7000, the heat transfer characteristics of the fluid of narrow annular channel was made by doing experiments and study. According to the result of the experiment, heat transfer coefficient and Reynolds number of function relation curves of Re-and Re-K are made. It was found that narrow ring channel has the remarkable strengthening effect with compact structure. Decreasing of the narrow gap dimension, the heat transfer coefficient increases.

scholarly journals Flow and heat transfer characteristics around an elliptic cylinder placed in front of a curved plate

2014 ◽  
Vol 18 (2) ◽  
pp. 465-478
Author(s):  
Mahmoud Mostafa ◽  
Radwan Kamal ◽  
Mohamed Gobran
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Angle Of Attack ◽  
Elliptic Cylinder ◽  
Heat Transfer Characteristics ◽  
Number Range ◽  
Transfer Characteristics ◽  
Reynolds Number Range

An experimental investigation has been conducted to clarify heat transfer characteristics and flow behaviors around an elliptic cylinder. Also, flow visualization was carried out to clarify the flow patterns around the cylinder. The elliptic cylinder examined has an axis ratio of 1:2.17, was placed in the focus of parabolic plate. The test fluid is air and the Reynolds number based on the major axis length, c, ranged from 5 x 103 to 3 x 104. The angle of attack (?) was changed from 0? to 90? at 15? interval. It is found that the pressure distribution, form drag, location of separation point, and heat transfer coefficient depend strongly upon the angle of attack. Over the Reynolds number range examined, the mean heat transfer coefficient is at its highest at ? = 60? - 90?. The values of heat transfer coefficient in the case of free cylinder are higher than those for cylinder/plate combination at all angles of attack and Reynolds number range examined.

Investigation on Heat Transfer Characteristics of Water Through Narrow Annulus

2006 ◽  
Author(s):  
Guangyao Lu ◽  
Jing Wang
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Heat Removal ◽  
Heat Transfer Characteristics ◽  
Number Range ◽  
Transfer Characteristics ◽  
Lower Reynolds Number ◽  
Axial Heat

A study is carried out to investigate the forced convective heat transfer characteristics of water through narrow annulus. For most works undertaken before were mainly concerned with the heat transfer characteristics of heat removal systems, the experiments herein are conducted to detect the heat transfer characteristics of heated fluid, as well as cooled fluid, flowing through narrow annulus. In the experiments, directions of flow include horizontal, upstream and downstream. The Reynolds number range, based on the annular hydraulic diameter, of 10 to 30,000 is covered in the experiments. During the experiments, the transitions from laminar to turbulent convective heat transfer are carefully observed. It is found that fully turbulent convective heat transfer is achieved at a lower Reynolds number in narrow annulus than that in larger tubes. When the Reynolds number is lower than 150, the heat transfer is degraded attributed to the slow flow rate and axial heat conduction. The experimental results indicate that the heat transfer characteristics of narrow annular flow are different from that of lager, more conventionally sized pipe flow. A convective heat transfer correlation is developed and the comparisons are made with the correlations of other works.

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