Numerical investigation of forced convection in a plane channel with a built-in triangular prism

Magherbi

Hidouri

et al. 2011

Natural convection in an inclined rectangular cavity filled with air is numerically investigated. The cavity is heated and cooled along the active walls whereas the two other walls of the cavity are adiabatic. Entropy generation due to heat transfer and fluid friction has been determined in transient state for laminar natural convection by solving numerically: the continuity, momentum and energy equations, using a Control Volume Finite Element Method. The structure of the studied flows depends on four dimensionless parameters which are: the thermal Grashof number, the inclination angle, the irreversibility distribution ratio and the aspect ratio of the cavity. The obtained results show that entropy generation tends towards asymptotic values for lower thermal Grashof number values, whereas it takes an oscillative behavior for higher values of thermal Grashof number. Transient entropy generation increases towards a maximum value, then decreases asymptotically to a constant value that depends on aspect ratio of the enclosure. Entropy generation increases with the increase of thermal Grashof number, irreversibility distribution ratio and aspect ratio of the cavity. Bejan number is used to measure the predominance of either thermal or viscous irreversibility. At local level, irreversibility charts show that entropy generation is mainly localized on bottom corner of the left heated wall and upper corner of the right cooled wall.

Section: Numerical Proceduresmentioning

confidence: 99%

Entropy Generation at Natural Convection in an Inclined Rectangular Cavity

Magherbi

Hidouri

et al. 2011

“…The used numerical code, described and validated in detail in Abbassi et al [18], employs the Control Volume Finite Element Method (CVFEM) of Patankar [17] and Saabas and Baliga [19]). Note that the SIMPLE algorithm was developed at Imperial College-London by Pantakar and Spalding [20].…”

Section: Methodsmentioning

confidence: 99%

Numerical Study of Entropy Generation in Mixed MHD Convection in a Square Lid-Driven Cavity Filled with Darcy–Brinkman–Forchheimer Porous Medium

Bouabda

Brahim

et al. 2016

This investigation deals with the numerical simulation of entropy generation at mixed convection flow in a lid-driven saturated porous cavity submitted to a magnetic field. The magnetic field is applied in the direction that is normal to the cavity cross section. The governing equations, written in the Darcy-Brinkman-Forchheimer formulation, are solved using a numerical code based on the Control Volume Finite Element Method. The flow structure and heat transfer are presented in the form of streamlines, isotherms and average Nusselt number. The entropy generation was studied for various values of Darcy number (10 −3 ≤ Da ≤ 1) and for a range of Hartmann number (0 ≤ Ha ≤ 10 2 ). It was found that entropy generation is affected by the variations of the considered dimensionless physical parameters. Moreover, the form drag related to the Forchheimer effect remains significant until a critical Hartmann number value.

“…The SIMPLER algorithm and the SIMPLEC approximation of Van Doormal and Raithby are used in conjunction with an Alternating Direction Implicit (ADI) Scheme for performing the time evolution. The used numerical Code written in FORTRAN language was described and validated in details in Abbassi et al [39,40] …”

Section: Numerical Proceduresmentioning

confidence: 99%

Analysis of the Magnetic Field Effect on Entropy Generation at Thermosolutal Convection in a Square Cavity

Hidouri

Magherbi

et al. 2011

Thermosolutal convection in a square cavity filled with air and submitted to an inclined magnetic field is investigated numerically. The cavity is heated and cooled along the active walls with a mass gradient whereas the two other walls of the cavity are adiabatic and insulated. Entropy generation due to heat and mass transfer, fluid friction and magnetic effect has been determined in transient state for laminar flow by solving numerically the continuity, momentum energy and mass balance equations, using a Control Volume Finite-Element Method. The structure of the studied flows depends on four dimensionless parameters which are the Grashof number, the buoyancy ratio, the Hartman number and the inclination angle. The results show that the magnetic field parameter has a retarding effect on the flow in the cavity and this lead to a decrease of entropy generation, Temperature and concentration decrease with increasing value of the magnetic field parameter.