Ravi Shankar Prasad^a , S.N. Singh^b , Amit Kumar Gupta^c,*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-15, 2018, DOI:10.5098/hmt.11.28

Abstract This paper presents the results of numerical analysis of steady laminar natural convection and surface radiation in the two dimensional partially right side open square cavity filled with natural air (Pr = 0.70) as the fluid medium. The cavity has left isothermal hot wall with top, bottom and right adiabatic walls. In the present study, the governing equations i.e. Navier-Stokes Equation in the stream function – vorticity form and Energy Equation are solved for a constant thermophysical property fluid under the Boussinesq approximation. For discretization of these equations, the finite volume technique is used. For the radiation calculations, the radiosity-irradiation… 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 >

Ravi Shankar Prasad^a,*, S.N. Singh^b, Amit Kumar Gupta^c

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.16

Abstract The results of numerical analysis of coupled laminar natural convection and surface radiation in a two-dimensional closed square cavity with the uniformly heated bottom wall, linearly heated vertical side wall(s) and the adiabatic top wall is discussed. The cavity is filled with natural air (Pr = 0.70) as the fluid medium. In the present study, the governing equations i.e., the Navier-Stokes Equation in the stream function – vorticity form and the Energy Equation are solved for a constant property fluid under the Boussinesq approximation. For discretization of these equations, the finite volume technique is used. For the radiation calculations, the… More >

Ravi Shankar Prasad^a,*,†, Ujjwal Kumar Nayak^a, Rajen Kumar Nayak^a, Amit Kumar Gupta^b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-7, 2022, DOI:10.5098/hmt.19.4

Abstract This paper presents the results of numerical analysis of coupled laminar natural convection and surface radiation in a two-dimensional closed square cavity with the inversely linearly heated vertical opposite side walls and the adiabatic top and bottom walls. The cavity is filled with natural air (Pr = 0.70) as the fluid medium. In the present study, the governing equations i.e., Navier-Stokes Equation in the stream function - vorticity form and Energy Equation are solved for a constant property fluid under the Boussinesq approximation. For discretization of these equations, the finite volume technique is used. For the radiation calculations, the radiosity-irradiation… More >

Mehdi Moslemi¹, Motahare Mahmoodnezhad¹, S. A. Edalatpanah^1,*, Sulima Ahmed Mohammed Zubair², Hamiden Abd El-Wahed Khalifa^2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.3, pp. 1957-1973, 2023, DOI:10.32604/cmes.2022.021481

Abstract In this research, a numerical study of mixed convection of non-Newtonian fluid and magnetic field effect along a vertical wavy surface was investigated. A simple coordinate transformation to transform wavy surface to a flat surface is employed. A cubic spline collocation numerical method is employed to analyze transformed equations. The effect of various parameters such as Reynolds number, volume fraction 0-, Hartmann number, and amplitude of wave length was evaluated in improving the performance of a wavy microchannel. According to the presented results, the sinusoidal shape of the microchannel has a direct impact on heat transfer. By increasing the microchannel… More >

Ting Zhang¹, Denghao Wu^1,2,*, Shijun Qiu², Peijian Zhou¹, Yun Ren³, Jiegang Mou¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1349-1361, 2022, DOI:10.32604/fdmp.2022.019617

Abstract Stall phenomena increase the complexity of the internal flow in centrifugal pump impellers. In order to tackle this problem, in the present work, a large eddy simulation (LES) approach is applied to determine the characteristics of these unstable flows. Moreover, a vorticity identification method is used to characterize quantitatively the vortex position inside the impeller and its influencing area. By comparing the outcomes of the numerical simulations and experimental results provided by a Particle Image Velocimetry (PIV) technique, it is shown that an apparent “alternating stall” phenomenon exists inside the impeller when relatively small flow rate conditions are considered. The… More >

Zhiqi Zhou^*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1091-1100, 2021, DOI:10.32604/fdmp.2021.016618

Abstract A relevant way to promote the sustainable development of energy is to use hydropower. Related systems heavily rely on the use of turbines, which require careful analysis and optimization. In the present study a mixed experimental-numerical approach is implemented to investigate the related mixed water flow. In particular, particle image velocimetry (PIV) is initially used to verify the effectiveness of the numerical model. Then numerical results are produced for various conditions. It is shown that an increase in the guide vane opening can reduce the extension of the region where the fluid velocity is 0 at the inlet of the… More >

H. F. Wong^1,2, Muhammad Sohail³, Z. Siri¹, N. F. M. Noor^1,*

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 319-336, 2021, DOI:10.32604/cmc.2021.015710

Abstract The mechanism of viscous heating of a Newtonian fluid filled inside a cavity under the effect of an external applied force on the top lid is evaluated numerically in this exploration. The investigation is carried out by assuming a two-dimensional laminar in-compressible fluid flow subject to Neumann boundary conditions throughout the numerical iterations in a transient analysis. All the walls of the square cavity are perfectly insulated and the top moving lid produces a constant finite heat flux even though the fluid flow attains the steady-state condition. The objective is to examine the effects of viscous heating in the fully… More >

M. Krishna Prasad¹, G. Manpreet Kaur¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.2, pp. 107-125, 2017, DOI:10.3970/fdmp.2017.013.107

Abstract The slow steady rotation of a micropolar fluid spheroid whose shape deviates slightly from that of a sphere in concentric spheroidal container filled with Newtonian viscous fluid is studied analytically. The boundary conditions used are the continuity of velocity and stress components, and spin vorticity relation. The torque and wall correction factor exerted on the micropolar fluid spheroid is obtained. The dependence of wall correction factor on the micropolarity parameter, spin parameter, viscosity ratio and deformation parameter is studied numerically and its variation is presented graphically. In the limiting cases, the torque acting on solid spheroid in spheroidal container and… More >

G. C. Bourantas¹, E. D. Skouras^2,3, V. C. Loukopoulos⁴, G. C. Nikiforidis¹

CMES-Computer Modeling in Engineering & Sciences, Vol.64, No.2, pp. 187-212, 2010, DOI:10.3970/cmes.2010.064.187

Abstract Meshfree point collocation method (MPCM) is developed, solving the velocity-vorticity formulation of Navier-Stokes equations, for two-dimensional, steady state incompressible viscous flow problems in the presence of heat transfer. Particular emphasis is placed on the application of the velocity-correction method, ensuring the continuity equation. The Gaussian Radial Basis Functions (GRBF) interpolation is employed to construct the shape functions in conjunction with the framework of the point collocation method. The cases of forced, natural and mixed convection in a 2D rectangular enclosure are examined. The accuracy and the stability of the proposed scheme are demonstrated through three representative, well known and established… More >