Investigation of Rayleigh-Benard Convection Heat Transfer of Non-Newtonian Nanofluids-Power Law Model in a Square Enclosure

نوع: Type: thesis

مقطع: Segment: masters

عنوان: Title: Investigation of Rayleigh-Benard Convection Heat Transfer of Non-Newtonian Nanofluids-Power Law Model in a Square Enclosure

ارائه دهنده: Provider: Fatemeh Soltani Gholi Khani

اساتید راهنما: Supervisors: Mohammad Saeed Aghighi (Ph.D)

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Fazlollah Eskandari Manjili Amireh Nourbakhsh

زمان و تاریخ ارائه: Time and date of presentation: 2021 March 17 , 16:00

مکان ارائه: Place of presentation:

چکیده: Abstract: In this study, Rayleigh-Benard Convection Heat Transfer of non-Newtonian fluids-power model with nanoparticles in the cavity is investigated numerically. Partial differential equations that govern fluid flow and heat transfer (using the finite element method based on MATLAB coding), for different values of the Rayleigh number , Lewis number , Buoyancy ratio number () , Brownian motion parameter and Thermophoresis parameter ()), Within the power index range (), For a value of Prandtl number have been solved. The temperature, flow, and concentration fields in the cavity were analyzed using temperatur, flow, and concentration contours. The rate of heat transfer in different states was measured using local and average Nusselt numbers, local and average Sherwood numbers. The results show that the average Nusselt and Sherwood numbers decrease with increases Power Index. By the way, the Lewis number has little effect on heat transfer and flow but it does affect the mass transfer. The effect of the buoyancy parameter was also investigated, and according to the analysis, it was found that mass buoyancy overcomes thermal buoyancy by increasing the buoyancy parameter. As a result, concentration and temperature contours show an increase in concentration and a decrease in temperature, respectively. According to the studies performed on the effect of Brownian rotation and thermophoresis parameters, with the increase of the mentioned parameters, we see an increase in irregularities in the distribution of temperature and concentration. decreases or the power law and Oldroyd increases, the un-yield regions expand, which causes the changes in dominant heat transfer mode from convection to conduction. Key Words: Cavity, Natural convection, Rayleigh-Benard, non-Newtonian fluids , power law model, nanoparticles, Prandtl number, Rayleigh number, Lewis number, Buoyancy ratio number, Brownian motion parameter and Thermophoresis parameter, power index , Nusselt number, Sherwood number.

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