The Experts below are selected from a list of 492 Experts worldwide ranked by ideXlab platform

Nasir Ali - One of the best experts on this subject based on the ideXlab platform.

  • Theoretical analysis of Thermal Entrance Problem for blood flow: An extension of classical Graetz Problem for Casson fluid model using generalized orthogonality relations
    International Communications in Heat and Mass Transfer, 2019
    Co-Authors: Muhammad Waris Saeed Khan, Nasir Ali
    Abstract:

    Abstract An analysis of classical Graetz Problem is carried out for the case of fluid obeying the Casson constitutive equation. The considered model physically corresponds to the Thermal entry flow of blood in a duct. The governing equation for the premeditated Problem is investigated by employing the separation of variables approach in conjunction with the MATLAB built in package bvp4c for the calculation of the eigenvalues and related numerical solution of the eigenvalue Problem. The solution is computed for the case of uniform surface temperature boundary condition for both flat and circular geometries. The axial diffusion and viscous dissipation effects on temperature field are also taken into account. The expressions of bulk mean temperature and Nusselt number are presented and discussed in terms of the main effect brought by the yield stress parameter, Peclet number and Brinkman number. It is found that both local and mean Nusselt numbers for blood enhance considerably with the increase of dimensionless plug radius and Brinkman number. In contrast, the Thermal Entrance length reduces with the rise of Peclet number. The results of present analysis have potential applications in development of nano fluidic, microfluidic and bio-medical devices used in haemodialysis and oxygenation.

Muhammad Waris Saeed Khan - One of the best experts on this subject based on the ideXlab platform.

  • Theoretical analysis of Thermal Entrance Problem for blood flow: An extension of classical Graetz Problem for Casson fluid model using generalized orthogonality relations
    International Communications in Heat and Mass Transfer, 2019
    Co-Authors: Muhammad Waris Saeed Khan, Nasir Ali
    Abstract:

    Abstract An analysis of classical Graetz Problem is carried out for the case of fluid obeying the Casson constitutive equation. The considered model physically corresponds to the Thermal entry flow of blood in a duct. The governing equation for the premeditated Problem is investigated by employing the separation of variables approach in conjunction with the MATLAB built in package bvp4c for the calculation of the eigenvalues and related numerical solution of the eigenvalue Problem. The solution is computed for the case of uniform surface temperature boundary condition for both flat and circular geometries. The axial diffusion and viscous dissipation effects on temperature field are also taken into account. The expressions of bulk mean temperature and Nusselt number are presented and discussed in terms of the main effect brought by the yield stress parameter, Peclet number and Brinkman number. It is found that both local and mean Nusselt numbers for blood enhance considerably with the increase of dimensionless plug radius and Brinkman number. In contrast, the Thermal Entrance length reduces with the rise of Peclet number. The results of present analysis have potential applications in development of nano fluidic, microfluidic and bio-medical devices used in haemodialysis and oxygenation.

M. M. Awad - One of the best experts on this subject based on the ideXlab platform.

  • Heat transfer for laminar Thermally developing flow in parallel-plates using the asymptotic method
    2010 3rd International Conference on Thermal Issues in Emerging Technologies Theory and Applications, 2010
    Co-Authors: M. M. Awad
    Abstract:

    Heat transfer for laminar, Thermally developing flow in parallel-plates is investigated using the asymptotic method. There are two asymptotes for local, and mean Nusselt numbers (Nuz and Num) in the parallel-plates Thermal Entrance Problem at both uniform wall temperature (UWT) and uniform heat flux (UHF). The first asymptote corresponds to very small value of dimensionless axial coordinate (z*). The second asymptote corresponds to very high value of dimensionless axial coordinate (z*). Using the methods discussed by Churchill and Usagi (1972, “General Expression for the Correlation of Rates of Transfer and Other Phenomena,” AIChE J., 18(6), pp. 1121-1128), the fitting parameter in the proposed model can be determined. Comparisons of the asymptotic model with the analytical and numerical solutions available in the literature are presented.

B. Keller - One of the best experts on this subject based on the ideXlab platform.

  • Effect of viscous dissipation on Thermally developing forced convection duct flows (Research Report 13/2005)
    ETH - Chair of Physics of Buildings, 2005
    Co-Authors: A. Barletta, E. Magyari, B. Keller
    Abstract:

    A self-contained treatment of laminar duct-flow heat transfer is performed. The presentation includes all the necessary definitions and results which are required for the treatment of the Thermal Entrance Problem in a duct with an arbitrary cross section. The special cases of a plane-parallel channel and of a circular duct are discussed in detail. A comparison is made between the results obtained when viscous dissipation is taken into account and those which are obtained when this effect is neglected. The treatment of the effect of viscous dissipation presented here differs from previous approaches available in the literature. The difference relies mainly in the prescription of the initial condition at the Entrance cross-section. Unlike in similar treatments available in the literature, the effect of viscous dissipation is taken into account self-consistently, i.e. both upstream and downstream of the Entrance section

M’hamed Boutaous - One of the best experts on this subject based on the ideXlab platform.

  • Thermally Developing Heat Transfer With Nonlinear Viscoelastic and Newtonian Fluids With Pressure-Dependent Viscosity
    Journal of Heat Transfer, 2018
    Co-Authors: Dennis A. Siginer, F. Talay Akyildiz, M’hamed Boutaous
    Abstract:

    A semi-analytical solution of the Thermal Entrance Problem with constant wall temperature for channel flow of Maxwell type viscoelastic fluids and Newtonian fluids, both with pressure dependent viscosity, is derived. A Fourier–Gauss pseudo-spectral scheme is developed and used to solve the variable coefficient parabolic partial differential energy equation. The dependence of the Nusselt number and the bulk temperature on the pressure coefficient is investigated for the Newtonian case including viscous dissipation. These effects are found to be closely interactive. The effect of the Weissenberg number on the local Nusselt number is explored for the Maxwell fluid with pressure-dependent viscosity. Local Nusselt number decreases with increasing pressure coefficient for both fluids. The local Nusselt number Nu for Newtonian fluid with pressure-dependent viscosity is always greater than Nu related to the viscoelastic Maxwell fluid with pressure-dependent viscosity.