Investigation the economics of rotary type heat exchangers

In this doctorate thesis, velocity and temperature fields inside a heated closed enclosure were numerically and experimentally investigated. In numerical part, four different problems were solved numerically. These are a sidewall heated closed enclosure, a bottom wall heated closed enclosure, natural convection with forced convection at the same direction and natural convection with forced convection at opposite direction. For every problem, according to the numerical results obtained, dimensionless resultant velocity, dimensionless horizontal velocity, dimensionless vertical velocity values were given. For three different sections of closed enclosure, dimensional horizontal and vertical velocities were presented. Velocity and temperature maps were formed and for three different sections dimensional temperature variation charts were drawn. In addition, for sidewall heated closed enclosure problem a heat transfer correlation was given. For numerical studies CFD software Fluent 6.0 was used. The experimental part of the thesis has two parts. In the first part, for four different problems experimental velocity measurements were done. Experimental studies were performed at the same boundary conditions with numerical solutions. For velocity measurements PIV (Particle Image Velocimetry) system was used. PIV system was preferred. Because it does not spoil streamlines and gives velocity vectors in a short time. It was investigated if PIV measurements of small velocities happened in the enclosure are reliable and it is indicated that measurements of the system were true. In this part of the study, dimensionless resultant velocity, dimensionless horizontal velocity, dimensionless vertical velocity values obtained from measurements were given. For three different sections of the enclosure dimensional horizontal and vertical velocity distributions were presented. In the second part, using totally 100 J type thermocouples temperature measurements were done. After measurements, for four different problems dimensionless temperature distributions within heated closed enclosure were given. And temperature maps obtained from numerical solutions were verified experimentally. In the last part of the thesis, numerical and experimental results were compared. For velocity and temperature distributions numerical and experimental results are in agreement. In addition, numerically obtained heat transfer correlation was compared to similar studies in literature and seen that it agrees with the literature.