Transient three-dimensional natural convection in inclined confined

مقدم أطروحة جامعية

Hasan, Wajih Kamal

الجامعة

الجامعة التكنولوجية

الكلية

قسم هندسة المكائن و المعدات

دولة الجامعة

العراق

الدرجة العلمية

دكتوراه

تاريخ الدرجة العلمية

2006

الملخص الإنجليزي

Transient three-dimensional natural convection in inclined confined fluid-saturated porous media had been investigated experimentally and numerically through this work.

The geometry selected is a box with insulated vertical sides and constant wall temperature at the top.

The bottom boundary conditions take three states: constant wall temperature and time-periodic is covered in the numerical study and the constant heat flux in the experimental work.

Through the experimental work, an experimental rig is constructed in a form of box filled with fluid-saturated porous material and heated from the bottom by an electric heater.

The distilled water is chosen as a saturation fluid while the sand is chosen as the porous material.

The values of the heat transfer rate are chosen to be approximately (144 W, 168 W, 192 W, 216 W and 240 W).

In the numerical investigation, the momentum equation of flow through fluid-saturated porous media had been transformed to a vector potential form and solved numerically using the Successive Over Relaxation method while the energy equation is solved using the three-dimensional Alternating Direction Implicit method.

The values of the Rayleigh number under investigation are (60, 70, 80, 90 and 100) and the inclination angles are (0°, 15° and 30°).

The results are presented in a form of contour maps for the temperature and a velocity vector maps for the velocity.

From the numerical study, the results reveal that the temperature within the box is increased as the time, Rayleigh number or the inclination angle increase.

The Nusselt number varies inversely with the time and directly with the Rayleigh number and the angle of inclination.

From the time-periodic boundary condition case, two cell convective patterns are obtained in the z-x plane, and it transforms to one cell convective pattern within.

Increase in the incHnatioi Langley.

Also, the Nusselt number variation is in a amplitude or decreasing the period does not affect the general shape of the temperature and velocity vector distributions or the Nusselt number periodic shape.

The experimental results show that the temperature values within the box vary inversely with the box height and directly with the time in a form of curvilinear isothermal lines.

Wavy temperature distribution pattern is deduced along the horizontal x-axis.

Increasing the Rayleigh number or the inclination angle will result in a rapid increase in the temperature value.

Also, the Nusselt number varies inversely with the time and the inclination angle.

Correlation equation obtained from the experimental work showed a relation between the Nusselt number, Time, Rayleigh number and the inclination angle.

The comparison with the previous works and between the experimental and theoretical works shows a good agreement.

Nusselt number error analysis presents an error of 3.3.

التخصصات الرئيسية

الهندسة الميكانيكية

الموضوعات

• النماذج الرياضية

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-305884