Optimal Natural Convection Heat Transfer Improvement by Combining Periodic Heating Temperature, Cavity Inclination, and Nanofluid. Issue 10 (3rd July 2017)

• Record Type: Journal Article
• Authors: Hati, Mourad; Raji, Abdelghani; Hasnaoui, Mohammed; Naïmi, Mohamed; El Abdallaoui, Mohamed
• Is Part Of: Heat transfer engineering. Volume 38:Issue 10(2017)
• Page Start: 931
• Page End: 947
• Publication Date: 2017-07-03
• Subjects: Heat -- Transmission -- Periodicals; 621.4022
• DOI: 10.1080/01457632.2016.1212574
• Languages: English
• ISSNs: 0145-7632

Abstract

ABSTRACT: Natural convection within a square inclined cavity filled with Al2 O3 –water nanofluid is investigated numerically. The temperature of the cooled surface is maintained constant, while that of the opposite surface (heating temperature) is varied sinusoidally in time. The remaining walls are considered adiabatic. The parameters governing the problem are the amplitude and the period of the variable temperature, the Rayleigh number, the inclination of the cavity, and the solid volume fraction. A substantial enhancement of heat transfer is obtained by combining the beneficial effects of the variable heating temperature (via its period and amplitude), the inclination of the cavity, and the nanoparticles fraction. In comparison with the constant heating conditions, it is found that both the variable heating temperature and the inclination of the cavity may lead to drastic changes in the flow structure and the corresponding heat transfer. The resonance phenomenon, observed for critical periods of the exciting temperature, is amplified by adding Al2 O3 nanoparticles to the base fluid.