ABSTRACT Hydrodynamic behavior of developing laminar wavy falling film has been studied, experime... more ABSTRACT Hydrodynamic behavior of developing laminar wavy falling film has been studied, experimentally, in the presence of electrohydrodynamic conduction phenomenon. Electric field has been applied using nine pairs of flush mounted electrodes which can generate an EHD conduction pumping effect in the liquid film. Statistical characteristics of wavy falling film have been extracted and the effect of EHD conduction phenomenon on the wavy falling film behavior has been investigated in various Re numbers and applied voltages for two different inclination angles. Furthermore, two different operation cases for conduction pumps have been considered. The results show that applying of electric field on falling film using flush mounted electrodes, which does not alter the flow geometry and film original structure, can intensify the wavy behavior of laminar falling film. This effect is considerable for high Reynolds numbers in which large waves appear on the film surface. Comparison of operation cases show that the case with narrower high voltage electrode decreases the substrate thickness and can be the better choice for enhancement of heat/mass transfer.
Previous study of authors showed that τ− k turbulence model has a good accuracy for prediction of... more Previous study of authors showed that τ− k turbulence model has a good accuracy for prediction of hydrodynamic behaviour of near wall turbulence in a gas-solid boundary layer flow. In that study two-phase τ− k model was derived from Yokomine et al. modified ε− k ...
This paper presents a comparative-numerical investigation on film cooling from a row of simple an... more This paper presents a comparative-numerical investigation on film cooling from a row of simple and compound-angle holes injected at 35°on a flat plate with four film cooling configurations: (1) cylindrical film hole;
Computational results are presented for a row of coolant injection holes on each side of a high-p... more Computational results are presented for a row of coolant injection holes on each side of a high-pressure turbine blade near the leading edge. Seven hole configurations have been used to show the effect of various diffusion shaped holes and their trenching on film cooling effectiveness: (1) cylindrical film hole; (2) forward diffused film hole; (3) trenched forward diffused film hole;
... are solved using a 3-D finite-volume method that allows the use of arbitrary ... discharge pi... more ... are solved using a 3-D finite-volume method that allows the use of arbitrary ... discharge pipe an TC = 273 K. Zero gradient conditions are used at the outflow boundary. ... compound angle injections through cylindrical holes of Haslinger and Hennecke [12] are simulated as baseline ...
ABSTRACT Hydrodynamic behavior of developing laminar wavy falling film has been studied, experime... more ABSTRACT Hydrodynamic behavior of developing laminar wavy falling film has been studied, experimentally, in the presence of electrohydrodynamic conduction phenomenon. Electric field has been applied using nine pairs of flush mounted electrodes which can generate an EHD conduction pumping effect in the liquid film. Statistical characteristics of wavy falling film have been extracted and the effect of EHD conduction phenomenon on the wavy falling film behavior has been investigated in various Re numbers and applied voltages for two different inclination angles. Furthermore, two different operation cases for conduction pumps have been considered. The results show that applying of electric field on falling film using flush mounted electrodes, which does not alter the flow geometry and film original structure, can intensify the wavy behavior of laminar falling film. This effect is considerable for high Reynolds numbers in which large waves appear on the film surface. Comparison of operation cases show that the case with narrower high voltage electrode decreases the substrate thickness and can be the better choice for enhancement of heat/mass transfer.
Previous study of authors showed that τ− k turbulence model has a good accuracy for prediction of... more Previous study of authors showed that τ− k turbulence model has a good accuracy for prediction of hydrodynamic behaviour of near wall turbulence in a gas-solid boundary layer flow. In that study two-phase τ− k model was derived from Yokomine et al. modified ε− k ...
This paper presents a comparative-numerical investigation on film cooling from a row of simple an... more This paper presents a comparative-numerical investigation on film cooling from a row of simple and compound-angle holes injected at 35°on a flat plate with four film cooling configurations: (1) cylindrical film hole;
Computational results are presented for a row of coolant injection holes on each side of a high-p... more Computational results are presented for a row of coolant injection holes on each side of a high-pressure turbine blade near the leading edge. Seven hole configurations have been used to show the effect of various diffusion shaped holes and their trenching on film cooling effectiveness: (1) cylindrical film hole; (2) forward diffused film hole; (3) trenched forward diffused film hole;
... are solved using a 3-D finite-volume method that allows the use of arbitrary ... discharge pi... more ... are solved using a 3-D finite-volume method that allows the use of arbitrary ... discharge pipe an TC = 273 K. Zero gradient conditions are used at the outflow boundary. ... compound angle injections through cylindrical holes of Haslinger and Hennecke [12] are simulated as baseline ...
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