Transient Buoyancy- Driven Laminar Convection in an Inclined Three- Dimensional Trapezoidal Enclosure

Abstract

Numerical analysis of transient laminar threedimensionalbuoyancy-driven convection in an inclined threedimensionaltrapezoidal air-filled enclosure was investigated inthis paper. The right and left sidewalls of the enclosure arekept at constant cold temperatures. The bottom wall ismaintained at a constant hot temperature , while the top wall isconsidered adiabatic. Numerical investigation is performed forRayleigh numbers varied as 103 ≤ Ra ≤ 105 , while thetrapezoidal enclosure inclination angle is varied as 0° ≤  ≤180°. Prandtl number is considered constant at Pr = 0.71. Flowand thermal fields are presented in both two and threedimensionalpattern. Also, both local and average Nusseltnumbers are calculated and discussed. The results show thatwhen the Rayleigh number increases, the flow patterns arechanged especially in three-dimensional results and the flowcirculation increases. The minimum average Nusselt numberinside the trapezoidal cavity corresponds to the highestinclination angle [i.e., 180 ].While, the average Nusseltnumber reaches its maximum value at    30 . Moreover,when the Rayleigh number increases the average Nusseltnumber increases as expected.