Tuesday, July 9, 2013

5 Minutes with...Hamed Ghaednia

5 Minutes with...

Hamed Ghaednia, PhD Student, Mechanical Engineering at Auburn University

Hamed with his poster at the 2013 STLE Annual Meeting
What got you interested in tribology, and where has that interest led you? Looking back, I can recognize a couple of events over the course of my studies that prepared me and got me interested in the field of tribology.  While I was working on my undergrad I was offered to enter a double major program as part of an honors program.  I was given the choice to select a second major and I chose to study chemical engineering because of my fascination with chemical processes.  I did not know it at the time, but the mechanical/chemical engineering combination gave me a boost through my career in the field of tribology. My first exposure to tribology research was when I started working on my master’s degree.  I was looking for research topics that included both of my majors so I started working on the semi-active control of a rotor mounted on magneto-rheological journal bearings.  My research involved: numerical simulations of a rotors’ vibrations, MR fluid journal bearing modeling and design of a fuzzy control system.  My Master’s thesis was partly related to tribology. However, I had the opportunity to engage in a variety of research topics related to tribology when I began my PhD research at Auburn University.  That was when I began to really appreciate the complexity and interdisciplinary approach to tribology in solving unique and cutting edge problems, which got me interested in tribology. I have been active in the field of tribology ever since as a Research Assistant in the Multiscale Tribology Laboratory at the Auburn University and I have been involved in a range of topics such as nanotribology, lubrication and contact mechanics.

Can you give us some detail on your research? Currently, I am focused on the effect of nanoparticle additives on lubricants as my PhD project. Nano-sizes particles are small enough to infiltrate the small gaps between surfaces in contact and alter the tribological characteristics. However the particles’ exact enhancing mechanisms remain unknown (with a few exceptions). This project has different angles and challenges to be explored, such as stability of nanoparticle suspensions. Usually the base oils are non-polar so there is no strong intermolecular force available to suspend the particles. Nanoparticles change the bulk properties of the lubricants, such as viscosity and thermal conductivity, which need to be quantified. The main goal of the project is to understand the effect of particles on friction and wear and to study the interaction of particles with surfaces under high pressure.  This project involves a variety of different experimental techniques ranging from purely chemical tests to friction and surface analysis tests. In addition, I am working on developing a contact model for nanoparticles between rough surfaces. Therefore it is a very good opportunity for me to get involved in various tribological topics and try to increase my knowledge of tribology. I am two and half years into this project and have tackled multiple fronts of the project. Results so far are very interesting and I have couple of papers in publication and in preparation on the subject.

During my Master’s program I was working on magnetorheological (MR) journal bearings. MR bearings consist of a conventional bearings filled with the MR fluid.  MR fluid is a suspension of micron size ferromagnetic particles in a base oil. MR fluids’ viscosity and rheology changes under an applied external magnetic field that could be utilized to control the response of the bearing in a feedback control system.  The first goal of the study was to develop a heat transfer model for the bearings and explore the effect of temperature rise on the performance of the rotor-bearing system. The second goal was to design and implement a semi-active fuzzy control system to minimize the vibrations of the system.

What recommendations would you give to other students and researchers in the field? Grad school is usually stressful, lengthy and typically revolves around your research. Therefore take plenty of time to explore your possibilities and choose the research topic that you like and enjoy learning about. This can significantly improve your grad school experience.

As known, tribology mainly explores the contacts between different materials. These can be in different phases and are governed by different physical or chemical principles. Tribology links different physical and chemical concepts together in search of an answer.  Tribology does not stop at the edge of the materials; it bridges the gaps. Hence, if you are want to be involved in this field, my advice is to be willing to bridge the gaps and learn every day.

Any final thoughts you’d like to give readers? Don’t forget that many breakthroughs in the history of mankind came from early tribologists.  Examples of these are cavemen making fire out of friction and the invention of the first rolling element bearing, the wheel. Thus, it is probable that a tribologist will invent the next revolutionary device or discover the key to the next chapter of engineering!

For more info, click here to read The 10 Greatest Events in Tribology History (article and poster)

Hamed’s Favorites 
Tribology book/reference: Even though I use several tribology-related books on a regular basis, I can name three books as my favorites:

Favorite professor(s)/mentor(s): Dr. Jackson and Dr. Ohadi, my PhD and Master’s advisors, are my favorite professors and mentors.
Favorite online resource related to your research: http://www.tribology-abc.com/
Favorite quote:  “Believe those who are seeking the truth. Doubt those who find it.” – Andre Gide, French critic, essayist, & novelist (1869 - 1951)

Hamed Ghaednia received his BS degrees in Mechanical Engineering and in Chemical Engineering from the Tehran Polytechnic (also known as Amirkabir University of Technology), Iran, in 2007 and 2010, respectively. During his undergraduate he was a member of the Parsian Robotic Group and participated in several international robotic competitions and won awards. He received his MS degree in Mechanical Engineering from Tehran Polytechnic in 2010 while working as a Graduate Assistant for the Vibration and Noise Control Laboratory. He is currently pursuing his PhD in Mechanical Engineering, in the field of Tribology, at Auburn University. He is currently a Research Assistant at the Multiscale Tribology Laboratory. He has published papers in the fields of: nano particle lubricants, magneto-rheological fluid (MR fluid) bearings and contact mechanics. His current research involvements are nanoparticle lubricants, nanotribology and contact mechanics.

Mr. Ghaednia is a member of the Society of Tribologists and Lubrication Engineers (STLE) and American Society of Mechanical Engineers (ASME).

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