Amnart Boonloi^a, Withada Jedasadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-15, 2014, DOI:10.5098/hmt.5.19

Abstract 3D numerical investigations for heat transfer characteristics and flow configurations in a fin–and-oval-tube heat exchanger with V-tip pointing downstream delta winglet pairs (DDWP) are examined. The DDWPs are placed on the fin surface with pointing downstream and the oval tube row number is set at three in a staggered arrangement. The flow attack angles (θ = 15°, 30°, 45° and 60°) and the distance from V-tip to the oval tube center in transverse axis (a = 3.77, 4.77 and 5.77 mm) are investigated for Reynolds number based on hydraulic diameter, Re = 500 – 2500. The numerical results are compared… More >

Withada Jedsadaratanachai^a, Amnart Boonloi^b,*

Frontiers in Heat and Mass Transfer, Vol.6, pp. 1-19, 2015, DOI:10.5098/hmt.6.13

Abstract Numerical investigations on flow topology, heat transfer behavior and thermal performance evaluation in a circular tube heat exchanger with the punched delta winglet vortex generators (PDWVG) inserted in the middle of the test section are presented. The effects of the flow attack angles that converging to the center of the tube; α = 0°, 5°, 10°, 15°, 20°, 25°, and flow directions; winglet tips pointing downstream and upstream, are investigated for the Reynolds numbers; Re = 100 – 2000. The finite volume method and SIMPLE algorithm are used for the current study. The results are presented in terms of flow… More >

N. Ananda Reddy^a,*, P. Chandra Reddy^a , M.C. Raju^a , S.V.K.Varma^b

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-7, 2018, DOI:10.5098/hmt.10.4

Abstract A theoretical investigation has been performed to describe the laminar flow of a rotating fluid past a porous plate in conducting field with variable temperature and variable concentration taking into account the chemical reaction, radiation and Dufour effects. The non-dimensional governing equations are solved numerically by using finite difference scheme. The effects of different physical parameters on velocity, temperature and concentration are presented and discussed with the help of graphs. Also the numerical values for local skin friction, Nusselt number and Sherwood number are recorded and analyzed. Increasing values of heat source parameter results in rising of the temperature, but… More >

V. S. Sampath Kumar^a , N. P. Pai^a,† , B. Devaki^a

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-7, 2021, DOI:10.5098/hmt.16.3

Abstract A study is carried out for the two dimensional laminar flow of conducting fluid in presence of magnetic field. The governing non-linear equations of motion are transformed in to dimensionaless form. A solution is obtained by homotopy perturbation method and it is valid for moderately large Reynolds numbers for injection at the wall. Also an efficient algorithm based finite difference scheme is developed to solve the reduced coupled ordinary differential equations with necessary boundary conditions. The effects of Reynolds number, the magnetic parameter and the pradantle number on flow velocity and tempratare distribution is analysed by both the methods and… More >

Abderraouf Dahmani^a,∗ , José Muñoz-Cámara^b, Juan Pedro Solano^b, Samir Laouedj^a

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.42

Abstract In this paper, a steady and laminar flow of ferrofluid (Fe₃O₄/Water) in a uniformly heated tube under the effect of non-uniform magnetic field arranged periodically along the tube is numerically analyzed using the finite volume method. The analysis sheds light on the flow pattern, Nusselt number, friction factor and the Performance Evaluation Criterion, at laminar flow regime (10² ≤ Re ≤ 10³ ) and for various magnetic numbers (Mn = 0, 2.83 · 10⁴ , 6.37 · 10⁴ and 1.13 · 10⁵ ). The obtained results show that the magnetic field generated by periodic arrangement of the wire pitches, forces… More >

Scott Wahlquist^a, Amir Ali^a,b,*, Su-Jong Yoon^c, Piyush Sabharwall^c

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.35

Abstract The heat transfer performance of a novel tube configuration that combines the swirling velocity induced by oval-twisting and secondary flow generated by a helical geometrical flow path is presented. The Nusselt number (Nu) and friction factor (f) are compared for the laminar flow regime (Re = 250- 2000) under isothermal wall conditions. Under the same flow and boundary conditions, the oval-twisted helical tube increased the Nu and slightly increased the f over the circular helical tube. The best performance with the highest Nuand lowest f occurs at the coil curvature ratio (d_h/D) of 0.17. The quantified enhancement performance factor (h)… More >

Mei Su^a , Ligai Kang^b, Kangjie Sun^b,*

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-5, 2022, DOI:10.5098/hmt.18.22

Abstract To study the heat transfer effect of rough surface in laminar flow, the direction splitting method is introduced by fully developed fields for solving the Navier–Stokes equations of incompressible flow in assuming two-dimension. Firstly, the algorithm of the incompressible Navier–Stokes equations with pressure correct is carried out. Secondly, the effects of pressure drop and heat transfer are investigated in different rough surface elements which are configured with triangular and rectangular elements. The Reynolds number, roughness element spacing, and roughness height are also considered as the factors which affect the heat transfer. The results indicate that the parallel present method reaches… More >

Shrikant Arunrao Thote^*, Netra Pal Singh

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 501-511, 2023, DOI:10.32604/fdmp.2022.021502

Abstract The thermal behavior of pipes with a twisted tape inside (used to enhance heat transfer through the tube wall) is studied in the laminar flow regime. Oil is used as the work fluid with the corresponding Reynolds Number spanning the interval 200–2000. It is found that in such conditions the ‘Nusselt Number’ (Nu) gradually increases with reducing the tape twist ratio, whereas the friction factor is detrimentally affected by the presence of the tape (as witnessed by the comparison with the companion case where a plain tube is considered). In particular, it is shown that the heat transfer efficiency can… More >

Lijian Xu¹, Tianyang Yang², Lekang Yin³, Ye Kong², Yuri Vassilevski^4,5, Fuyou Liang^1,5,6,*

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.2, pp. 509-526, 2020, DOI:10.32604/cmes.2020.010719

Abstract Computational modeling methods have been increasingly employed to quantify aortic hemodynamic parameters that are challenging to in vivo measurements but important for the diagnosis/treatment of aortic disease. Although the presence of turbulence-like behaviors of blood flow in normal or diseased aorta has long been confirmed, the majority of existing computational model studies adopted the laminar flow assumption (LFA) in the treatment of sub-grid flow variables. So far, it remains unclear whether LFA would significantly compromise the reliability of hemodynamic simulation. In the present study, we addressed the issue in the context of a specific aortopathy, namely aortic dilation, which is… More >