The Engineering Faculty of Stellenbosch University honours the life and legacy of Prof Paul Johan Erens, a distinguished scholar, mentor and industry leader. Through his expertise in thermodynamics, fluid mechanics and heat transfer, he shaped both academia and industry, leaving a lasting impact on engineering education and research.
Prof Erens earned his BSc (Eng) in 1967 and MSc (Eng) in 1972 at the University of Pretoria. After his studies, he joined the Council for Scientific and Industrial Research (CSIR), conducting research on pulverized coal combustion. While completing his MSc, he also lectured at the University of Pretoria. In 1973, he worked in bioengineering at Groote Schuur Hospital in Cape Town. He then pursued his PhD (Eng) at Stellenbosch University, completing it in 1982 under the supervision of Prof Detlev Kröger. His groundbreaking research on liquid-metal condensation positioned him as a leading expert in heat transfer.
His academic career spanned over four decades. After working at the Council for Scientific and Industrial Research (CSIR) on pulverised coal combustion and lecturing at the University of Pretoria, he joined Stellenbosch University in 1974 as a senior lecturer. He was promoted to professor in 1983 and served 11 years as Chair of the Department of Mechanical and Mechatronic Engineering, shaping the education of generations of engineers.
Prof Erens was known for his strict standards and rigorous teaching, particularly in Thermodynamics B, where punctuality and discipline were non-negotiable. Despite his demanding expectations, he was deeply invested in his students’ success. Many credit him for their academic and professional growth, including one former student who pursued a PhD at TU Delft thanks to his encouragement.
Beyond the lecture hall, he mentored numerous postgraduate students, including two PhD candidates (Alex Dreyer and Johan Kotze) and five master’s students (Alex Dreyer, Torsten Schultz, John Thacker, Randolph Oosthuizen and Dawie Kriel). His mentorship extended beyond research, offering students hands-on experience in his laboratory and guiding them towards industry success.
Prof Erens played a key role in bridging academia and industry, particularly through his collaboration with Industrial Water Cooling (IWC) alongside Prof Kröger. His expertise in heat exchangers and cooling tower technologies gained international recognition, leading to innovative computational models that continue to influence the field. His efforts established a strong partnership between IWC and Stellenbosch University, fostering industrial collaboration that enhanced engineering design. Eventually, he transitioned to a full-time role at IWC, where he continued to drive technological advancements in cooling systems.
Beyond his professional achievements, Prof Erens was a mentor and friend who shaped the careers of many engineers across South Africa and beyond. He was known for his discipline, integrity and dedication to the pursuit of knowledge. One former student, Prof Hanno Reuter, recalled how he stepped in as a mentor after his father’s passing, offering both academic and personal support. His influence extended far beyond engineering – he impacted lives.
Prof Paul Erens was a formidable academic, mentor and industry collaborator, and his dedication, accuracy and industry impact leave behind a legacy. He will be remembered.
