Rayleigh benard convection in nanoliquids

Abstract

Rayleigh-Benard convection in nanoliquids is studied in the presence of volumetric heat ´ newlinesource. The present analytical work concerns twenty nanoliquids. Carrier liquids considered newlineare water, ethylene glycol, engine oil and glycerine and with them five different newlinenanoparticles considered are copper, copper oxide, silver, alumina and titania. Expression newlinefor the thermophysical properties of the nanoliquids is chosen from phenomenological newlinelaws or mixture theory. Heat source is characterized by an internal nanoliquid newlineRayleigh number. Heat source adds to the energy of the system and hence an advanced newlineonset is observed in this case compared to the problem with no heat source. In the case newlineof heat sink, however, heat is drawn from the system leading to delay in onset. The individual newlineeffect of all the nanoparticles is to advance convection. Enhanced heat transport newlinesituation is observed in each of the nanoliquids with engine-oil-silver transporting maximum newlineheat and water-titania the least. Additional Fourier modes are found not to have newlineany profound effect on the results predicted by minimal modes. The connection between newlinethe Lorenz model and the Ginzburg-Landau model is clearly shown in the paper newline newline