Investigation of heat source distribution on heat and mass transfer in a cavity

نوع: Type: thesis

مقطع: Segment: masters

عنوان: Title: Investigation of heat source distribution on heat and mass transfer in a cavity

ارائه دهنده: Provider: Zahed karimi bahar

اساتید راهنما: Supervisors: Mohammadsaeed Aghighi (ph. D)

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Mohsen godarzi . amireh nour bakhsh

زمان و تاریخ ارائه: Time and date of presentation: 2024

مکان ارائه: Place of presentation: Faculty of Engineering

چکیده: Abstract: In this research, the effect of thermal source distribution on the manner and amount of mass and heat transfer in a fluid within a chamber has been investigated. Depending on the type of fluid and the type of heat transfer, the governing equations, including continuity, momentum, energy, and concentration, have been formulated in a differential form and analyzed numerically based on the finite element method using MATLAB coding. It was assumed that the chamber is heated from below and cooled from the sides, with the upper wall of the chamber being insulated. The hot surface below is considered to be half of the lower wall. However, in three scenarios, it has been modeled as a single continuous hot surface, two hot surfaces, and three distributed hot surfaces. The amount of mass and heat transfer in each condition has been calculated and compared with the other scenarios. The fluid studied in this research is considered to be of both Newtonian and non-Newtonian types, specifically the viscoplastic (Bingham) model, and by comparing them, a comprehensive view of the performance of different fluid types has been obtained. Furthermore, by selecting various Rayleigh numbers, the effect of the intensity of buoyancy forces on the problem has been examined in all cases. The results indicate that with an increase in the number of hot source segments, the temperature and concentration fields expand and a stronger flow is formed; additionally, the Nusselt number has increased. It has also been observed that the Rayleigh number is one of the parameters that has the most significant impact on the variations of the fields. Moreover, with the change of the fluid's yield stress from Newtonian to non-Newtonian, a transition occurred, which caused the formation of plug regions in the fluid, negatively affecting the temperature distribution, Nusselt number and heat and mass transfer.