PhD Student Researcher
How Additive Manufacturing can be harnessed to make the next
generation of high-performance thermal cooling systems.
Heat transfer is an everyday part of life, ranging from household appliances to high tech engineering sectors such as aerospace and energy. Electronics cooling is a major application for thermal devices currently. We are all familiar with a laptop heating up on our knees, or your smartphone shutting down on a hot day. If electronic devices get too hot, performance will suffer. Therefore modern computers are ever more dependent on advanced cooling systems for reliability, The next generation of computers, data servers and other electronics now require high-efficiency cooling systems that provide more high cooling capacity but in a smaller size.
Modern manufacturing techniques can now offer new methods of developing high-efficiency heat management devices. Additive Manufacturing (or 3D printing) has shown remarkable potential in making these new thermal management systems from metal for the next generation of heat exchanging devices.
As a PhD researcher in the PEM Centre, Mohammadreza Kadivar is currently researching how additive manufacturing can be harnessed to make the next generation of high-performance cooling systems. Mohammadrezas’ research programme will apply experimental methods and computer simulations in the design and evaluation of the new techniques. Mohammadreza started his PhD at IT Sligo in April 2019 under the supervision of Dr David Tormey and Dr Gerard McGranaghan. He is also a member of I-Form, an Advanced Manufacturing Research Centre working on an industrial based project with the collaboration of Abbvie Sligo.
Most heat transfer devices deal with a cooling fluid that flows in a pipe or over a surface. Think of a fan blowing air over a surface or cooling water in your car. The fluid absorbs heat from the solid surface and dissipates it to ambient. However, there are limits to these processes, and the next stage of improved devices use a technique where the liquid is boiled, thus absorbing large amounts of thermal energy. The vapour with the stored heat is then condensed where it gives up this heat to ambient. This method if designed properly can handle large amounts of heat, and with low temperatures. These cooling systems involving liquid and vapour are known as “two-phase” systems and are now of focus in the thermal management world.
It has been shown that boiling and condensation are highly affected by liquid interaction with the heating surfaces. This is where Additive Manufacturing has unique advantages for such devices in two ways,
(i) any shape can be formed
(ii) almost any surface roughness can be generated.
Additive manufacture can create modified surfaces such as artificial roughness and complex structures that can enhance heat transfer. It also helps the manufacture of the entire heat transfer device in a one-step process. This eliminates several production steps and resulting in simpler device manufacture, easy customisation, yet retaining high thermal performance.
Scanning Electron Microscope (SEM) image of the surface roughness in a stainless steel part fabricated by Additive Manufacturing (3D printed)
Mohammadreza is applying the AM process to fabricate high-efficiency cooling systems. Employing the superior flexibility of AM techniques, he is developing, fabricating and testing cooling systems with enhanced design to address the problems on the way of improving their efficiency and performance. His focus is on both single-phase and two-phase cooling systems.
Mohammadreza’s research can contribute to several sectors. One area is cooling channels for conformal cooling of injection moulding processes. The other one, which is of a more general application, is the cooling of electronic devices using two-phase heat exchangers. His work includes the design, fabrication and testing the heat exchanger under different conditions to evaluate the performance of the cooling system. He is also using computer simulation to study different contributing factor that can influence the design of cooling systems. Similar to every system, heat transfer devices require optimisation in the design. For this reason, Mohammadreza is employing optimisation tools incorporated with computer simulation to optimise the structure and design of the cooling system.
Mohammadreza is currently completing a review paper and two research papers based on his work so far on the computer simulation of heat exchangers with rough surfaces to be submitted in late 2020.
Simulation results of heat transfer in a rough mini-channel
Mohammadreza mentioned, “working in the PEM Centre at IT Sligo is a great opportunity for me to work in a friendly environment. I can openly propose my ideas, and my supervisors always willingly accept and guide me through it. I have also been able to extend my professional network with experts in i-Form and Trinity College Dublin (TCD).”
“I am delighted to be working in an area that blends two cutting edge technologies of Additive manufacturing and two-phase heat transfer. I would like to express my appreciation to Dr Gerard McGranaghan and Dr David Tormey for their never-ending support and guidance,” he added.
“Mohammadeza’s research will contribute to the knowledge on surface roughness in evaporation and condensation, as well as in single-phase applications such as conformal cooling of injection moulds, currently a topic of relevance in mould making internationally,” says co-supervisor Dr Gerard McGranaghan of IT Sligo.
Mohammadreza received his bachelor's degree in Power Plant Engineering. He has always been inspired by mathematical sciences and its application in real-life problems. He believes that Mechanics is the gateway to the real world of mathematics and as Leonardo da Vinci said, "Mechanics is the paradise of the mathematical sciences because by means of it one comes to the fruits of mathematics". Mohammadreza also holds a Masters in Mechanical Engineering from Shiraz University, Iran, where he focused on modelling and simulation of heat transfer and its application in industries.
Before joining the PEM Centre, Mohammadreza worked as a Mechanical Engineering Supervisor in MAPNA Turbine Engineering and Manufacturing Company. He has participated in several research collaborations with different research institutes worldwide. Leading to journal publication on heat transfer in nanofluids, pulsating convective nanofluid flow, optimisation of thermal energy storage systems, and heat transfer in grinding processes.