The main objective of this research is to study the effect of rib arrangement on the distributions of the local heat transfer coefficient in a stationary channel. In this study, the ribs with square cross section were...The main objective of this research is to study the effect of rib arrangement on the distributions of the local heat transfer coefficient in a stationary channel. In this study, the ribs with square cross section were used to place on two side walls for study. The rib height-to-hydraulic diameter ratio （e/Dh） and the rib pitch- to-height （p/e） ratio were fixed at 0.133 and 10, respectively. Three different types of rib arrangement for inclined ribs, V-shaped ribs and inverted V-shaped ribs were investigated. The rib angle of attack （α） was varied from 30° to 90° for inclined ribs and 45° and 60° for both V-shaped and inverted V-shaped ribs, and compared at constant Reynolds number Re =30000. Thermal Liquid Crystal sheet was applied for evaluating the heat transfer distributions. The results showed that the average Nusselt number on surface with rib inclined angle at 60°, 45°, and 60° V-shaped ribs was improved up to about 20%, 25% and 30% higher than case of angle 90° and the rib inclined angle at 60° V-shaped ribs provided the highest Nusselt number covering largest area when compared to the other cases.展开更多
In this study,the measurement object is a flame propagating in a premixed burner with swirling flow in order to investigate unsteady flame behavior in a gas turbine premixer.During flashback,the flame propagating upst...In this study,the measurement object is a flame propagating in a premixed burner with swirling flow in order to investigate unsteady flame behavior in a gas turbine premixer.During flashback,the flame propagating upstream was visualized with a high-speed camera.Moreover,we established the technique to measure the instantaneous flow fields of unburned fuel-air mixture in a swirling premixed burner using particle image velocimetry(PIV).As a result,the characteristics of flame behavior propagating upstream were examined.And it was found that a low velocity region existed in the vicinity of the flame tip.The relationship between low velocity region and flame behavior was discussed in detail.展开更多
基金financially supported by the Royal Golden Jubilee Ph.D. program from the Thailand Research Fund (TRF) on contract No. PHD/0061/2557
文摘The main objective of this research is to study the effect of rib arrangement on the distributions of the local heat transfer coefficient in a stationary channel. In this study, the ribs with square cross section were used to place on two side walls for study. The rib height-to-hydraulic diameter ratio （e/Dh） and the rib pitch- to-height （p/e） ratio were fixed at 0.133 and 10, respectively. Three different types of rib arrangement for inclined ribs, V-shaped ribs and inverted V-shaped ribs were investigated. The rib angle of attack （α） was varied from 30° to 90° for inclined ribs and 45° and 60° for both V-shaped and inverted V-shaped ribs, and compared at constant Reynolds number Re =30000. Thermal Liquid Crystal sheet was applied for evaluating the heat transfer distributions. The results showed that the average Nusselt number on surface with rib inclined angle at 60°, 45°, and 60° V-shaped ribs was improved up to about 20%, 25% and 30% higher than case of angle 90° and the rib inclined angle at 60° V-shaped ribs provided the highest Nusselt number covering largest area when compared to the other cases.
文摘In this study,the measurement object is a flame propagating in a premixed burner with swirling flow in order to investigate unsteady flame behavior in a gas turbine premixer.During flashback,the flame propagating upstream was visualized with a high-speed camera.Moreover,we established the technique to measure the instantaneous flow fields of unburned fuel-air mixture in a swirling premixed burner using particle image velocimetry(PIV).As a result,the characteristics of flame behavior propagating upstream were examined.And it was found that a low velocity region existed in the vicinity of the flame tip.The relationship between low velocity region and flame behavior was discussed in detail.
