One of the main objectives of #HugYourEngine is to shine a spotlight on individuals who are helping make internal combustion engines cleaner and more efficient. This spotlight is on Mark Hoffman.
Mark is an Assistant Professor of Mechanical Engineering at Auburn University where he teaches thermodynamics, heat transfer, internal combustion engines, and advanced powertrain systems. Hoffman has 15 years of expertise in kinetically controlled combustion, multi-fuel combustion, mixing controlled combustion, in-cylinder heat transfer, thermal barrier coatings, catalytic emission systems, particulate emissions characterization, and waste heat recovery. Prior to his employment with Auburn University, Dr. Hoffman was a research assistant professor in Clemson University’s Department of Automotive Engineering where he also served as director for Clemson’s Automotive Engineering Certificate program. Dr. Hoffman received his B.S. in Mechanical Engineering from Union College (2003) and both his M.S. (2008) and Ph.D. (2012) from the University of Michigan (ME). His work has been published in numerous journals, including Applied Energy, IEEE Transactions on Control Systems Technology, SAE Journal of Engines, International Journal of Engine Research, ASME Journal of Gas Turbines and Power, and ASME Journal of Heat Transfer.
Kelly Senecal (KS): Why did you get started in combustion research?
Mark Hoffman (MH): I’ve had a lifelong passion for automobiles and grew up enthralled with anything horsepower related - fast cars, tractor pulls, you name it. My interest in vehicles spurred me to become an engineer, and eventually steered my course to researching advanced combustion strategies and in-cylinder heat transfer.
KS: What are you working on now?
MH: I’m currently engrossed in a collaborative DOE project on optimizing the engine and powertrain efficiency of connected heavy duty diesel trucks. The Auburn GAVLAB team has excellent experience with connected vehicle testing utilizing the Auburn National Center for Asphalt Technology test track. Utilizing their connected vehicle expertise in combination with my team’s powertrain efficiency knowledge is expected to enhance the efficiency of long haul trucking, helping stabilize the cost of goods sold. In addition, my combustion team is utilizing alternative biofuels to enhance advanced compression ignition combustion strategies in diesel engines. Owing to the stringent controls necessary for that fundamental work, the team will utilize a single-cylinder laboratory engine setup. Finally, I also utilize novel thermal barrier coatings to tailor the transient combustion chamber surface temperature for reduced heat transfer and efficiency gains.
KS: What does your lab look like?
MH: I’m currently commissioning my advanced combustion laboratory, which makes for both a challenging and exciting time. The dynamometer facility is primarily outfitted for single cylinder diesel engine testing with specific emphasis on utilization of alternative fuels. Besides a full cadre of combustion analysis instrumentation, the lab is also being outfitted for transient particulate emissions quantification. Simultaneously, my team and I have constructed mobile data acquisition and instrumentation platforms to support in-vehicle testing efforts like the connected vehicle DOE project. Sometimes, the real world application can provide the best test bed.
KS: What’s your favorite type of flame?
MH: While I find beauty in diffusion flames, my overall favorite is a premixed flame wrinkled by turbulence. The in-cylinder images are truly captivating!
KS: What’s your favorite fuel?
MH: I do have fond memories of using gasoline to remove cosmoline from shipped parts, but I’d have to say ether is my favorite fuel. There’s nothing like turning over a stubborn tractor on a cold winter morning using a quick dose of ether.
KS: What advice would you give students thinking about going into combustion research?
MH: It is an exciting time to be a combustion engineer. Combustion research is thriving as the automotive industry continues their push towards greater efficiency. And, don’t think that combustion research is only viable for those interested in thermal fluid science; there’s room for a variety of skill sets as controls become increasingly integrated with advanced combustion strategies.
KS: Is the IC Engine dead?
MH: Absolutely not! The energy density and power to weight ratio offered by modern IC engine platforms still dominate the alternative propulsion technologies. Even though electrification will continue to increase, hybrids will still contain an IC engine platform. Some people forget that fact because HEV has the word ‘electric’ in it! Of course, electrification can make sense in some markets, particularly those that predominantly produce their electricity from renewable sources. However, if the electricity used for a plug-in hybrid emits CO2 during its generation, then electric vehicles are on the same footing as IC engines from a life-cycle analysis perspective, especially once recycling of the lithium ion batteries is considered. Overall, the fastest way for society to curb transportation-based emissions is to enhance the efficiency of IC engines.
KS: How is your work helping improve fuel efficiency or reduce emissions?
MH: Improved efficiency and reduced emissions are the ever-present measuring stick for the entire combustion community, and I have been fortunate enough to work on a variety of topics that measure up well. Some of my industrially sponsored activities have influenced vehicles you see on the road today. For instance, an OEM sponsored effort produced age-adaptive emissions control strategies to enhance their new product lineups. Other projects were less mature on the commercialization time scale. For example, my team and I developed a real-time capable, hardware validated, parallel evaporator waste heat recovery control system for a Tier 1 supplier. In the long term, while my most fundamental work on kinetically controlled combustion strategies and engine heat transfer reduction is further removed from commercial adaptation, it aims to simultaneously increase engine efficiency and reduce emissions.