KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Author: search.filters.author.Promvonge, P.Subject: search.filters.subject.Laminar flow

Search Results

Now showing 1 - 3 of 3
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Laminar periodic flow and heat transfer in square channel with 30° inclined baffles
    (2010-12-06)
    Kwankaomeng, S.
    ;
    Jedsadaratanachai, W.
    ;
    Promvonge, P.
    A numerical investigation has been carried out to study laminar flow and heat transfer characteristics in a three-dimensional isothermal wall square-channel with 30° staggered angled-baffles. The computations are based on the finite volume method, and the SIMPLE algorithm has been implemented. The fluid flow and heat transfer characteristics are presented for Reynolds numbers based on the hydraulic diameter of the channel ranging from 100 to 1200. To generate a pair of stream wise counter-rotating vortex (P-vortex) flows through the tested channel, the baffles (like rectangular winglet) with the attack angle of 30° are mounted in tandem and staggered arrangement on both upper and lower walls of the test channel. Effects of different baffle heights at a single pitch ratio (PR=3) on heat transfer and pressure loss in the channel are studied. It is found that P-vortex flows created by the 30° baffle exist and help to induce impinging jets on a side wall and the upper and lower wall leading to drastic increase in heat transfer rate over the test channel. In addition, the increase in the baffle height results in the rise of Nusselt number and friction factor values. The computational results reveal that the optimum thermal enhancement factor of the baffle is about 2.9 at height of 0.15 times of the channel height.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Thermal behavior of laminar periodic channel flow over triangular baffles
    (2010-04-01)
    Nivesrangsan, P.
    ;
    Sripattanapipat, S.
    ;
    Eiamsa-Ard, S.
    ;
    Promvonge, P.
    Laminar periodic flow and heat transfer in a two dimensional horizontal channel with isothermal walls and with staggered triangular baffles are numerically investigated. The computations are based on the finite volume method, and the SIMPLE algorithm with QUICK scheme is implemented. The fluid flow and heat transfer characteristics are presented for Reynolds numbers based on the hydraulic diameter of the channel ranging from 100 to 600. Effects of different baffle tip angles on heat transfer and pressure loss in the channel are studied and the results of the triangular baffle are also compared with those of the flat baffle. It is observed that apart from the rise of Reynolds number, the reduction of the baffle tip angle leads to an increase in the Nusselt number and friction factor. According to the computational results for triangular baffles, the optimum thermal performance is found at the baffle angle of 5°, baffle height to channel height ratio of 0.5 and baffle spacing to channel height ratio of 1.0. In addition, the thermal performances of the 5°-10° triangular baffles are found to be higher than that of the flat baffle for all Reynolds numbers used. © 2010 American Institute of Physics.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Numerical investigation of laminar heat transfer in a square channel with 45° inclined baffles
    (2010-02-01)
    Promvonge, P.
    ;
    Sripattanapipat, S.
    ;
    Tamna, S.
    ;
    Kwankaomeng, S.
    ;
    Thianpong, C.
    A numerical investigation of laminar periodic flow and heat transfer in a three-dimensional isothermal-wall square channel fitted with 45° inclined baffles on one channel wall is carried out in the present work. The finite volume method is introduced and the SIMPLE algorithm has been implemented for all computations. The fluid flow and heat transfer characteristics are presented for Reynolds numbers ranging from 100 to 1200. The 45° baffle mounted only on the lower channel wall has a height of b and an axial pitch length (L) equal to channel height (H). Effects of flow blockage ratios, BR = b/H = 0.1-0.5, on heat transfer and pressure loss in the square channel are examined and also compared with the typical case of the transverse baffle (or 90° baffle). It is found that apart from the rise of Reynolds number, the increase in the blockage ratio with the attack angle (α) of 45° results in considerable increases in the Nusselt number and friction factor values. The use of the 45° baffle can help to generate a streamwise main vortex flow throughout the channel leading to fast and chaotic mixing of flow between the core and the wall regions. In addition, the computational results reveal that the significant increase in heat transfer rate is due to impingement jets induced by a longitudinal vortex pair (P-vortex) of flow, appearing on the upper, lower and baffle trailing end side walls. The appearance of vortex-induced impingement flows created by the baffles leads to the maximum thermal enhancement factor of about 2.2 at BR = 0.4 and Re = 1200. The enhancement factor of the 45° baffle investigated is found to be higher than that of the 90° baffle for all Reynolds numbers and baffle heights. © 2009 Elsevier Ltd. All rights reserved.