Department of Mechanical Engineering

University of Technology

Final Defense of a PhD dissertation

Titled Parametric Study for Artificial Roughness Effect on Flow Boiling of Binary Mixture in Microchannel

By:  Qahtan Adnan Abass Al-Nakeeb


Examination committee members:


Prof. Dr. Ihsan Y. Hussain


          Prof. Dr. Ihsan Y. Hussain

Asst. Prof. Dr. Abdulsattar J. M. Hassan

Asst. Prof. Dr. Ali L. Ekaid

Asst. Prof. Dr. Falah Fakher Hatem

By Supervision:

Prof. Dr. Ekhlas M. Fayyadh  

Asst. Prof. Dr. Moayed R. Hasan

Mr. Qahtan Adnan Abass Al-Nakeeb discussed his dissertation on 20th December 2021 at 9:00 am, which aimed to investigate the effect of heat flux, mass flux, and artificial nucleation sites (ANS) on the onset of nucleation, flow boiling instability, pressure drop, and heat transfer coefficient on both deionized water and binary mixture (water-ethanol) at sub-cooled conditions. Further, the effect degree of sub-cooled for deionized water and concentration for binary mixture were considered.


The major conclusions of this study are:

  • The onset of boiling depends on the amount of mass flow, as increasing the mass flow of the fluid delays the boiling start of both the deionized water and the binary mixture,
  • Increasing the inlet temperature of deionized water without saturation requires a higher heat flux to start boiling. In addition to reducing the amount of pressure drop through the microwave channel and reducing the heat transfer coefficient
  • The stability of boiling depended on the amount of fluid inlet temperature without saturation in addition to the amount of mass flow and the amount of concentration of the mixture.


The major recommendations of this study are:

  • The use of artificial vacuoles enhances the heat transfer performance highly via the microwave channel
  • The use of the binary mixture can reduce the instabilities of boiling as it avoids the drying of the channel wall (keeps it moist).
  • The increase in the number of vacuoles enhances pressure drop.

Congratulations! To our workmate Mr. Qahtan Adnan Abass Al-Nakeeb