How is applied science being developed in Ukraine? Where are centrifugal pumps, compressors and turbines used today? These and other questions are answered by Andrii Zahorulko, the Head of Volodymyr Martsynkovskyy Computational Mechanics Department of Sumy State University. Applied research in the field of seals, bearings, tribology, computational fluid dynamics and rotordynamics.
Dr. Andrii, you are the representative and the successor of the scientific school created by Professor Volodymyr Martsynkovskyy. Could you please tell us what you and his other successors are engaged in?
Yes, Volodymyr Martsynkovsky is, unfortunately, no longer with us, but I assure you that his scientific school continues to exist. I want to note that Prof. Martsynkovsky was the founder and the head of our General Mechanics and Machine Dynamics Department for a very long time. I can only speak of my own experience. My students (masters and PhD students) and I are mainly engaged in research in sealing technology for turbomachines, e.g. centrifugal pumps, compressors, and turbines. In particular, we deal with the issues of sealing of annular, stuffing box and face impulse seals and their rotorodynamic characteristics, i.e. the analysis of the influence of forces arising in the seals on the sealing and vibration of turbomachines. Prof. Martsynkovsky initiated this entire subject; he actively developed it, and we now continue his work. Moreover, I will say that now our department bears his name ‒ the Volodymyr Martsynkovskyy Computational Mechanics Department.
You are the academic advisor of the joint Ukrainian and French project. What is it dedicated to?
I was the academic advisor of the Ukrainian-French project in 2019-2020. This project was planned to be carried through for two years and is now over. It was dedicated to reducing pollutant emissions through energy-efficient sealing solutions. In fact, it concerned the comparison of the characteristics of traditional mechanical face seals, which are already actively used in industry, and still not very well known abroad innovative impulse seals, which have been developed at our department and which significantly reduce friction and wear of the seal, simultaneously increasing the durability of the whole unit (for example, a pump). This project will give us a great opportunity in the future to find sources for the implementation of these seals not only in Ukraine but also in France and other European countries.
Within the framework of this project, joint visits were planned, which took place in the first year of the project. This is my PhD student and I visiting the Pprime Institute of the University of Poitiers (France), and this is the visit of our French colleagues (Doctors Noel Brunettere and Jean Buyer) to Sumy State University. Last year, all visits were cancelled due to quarantine, so we held and participated in two joint sealing online conferences at the Pprime Institute (the 19th Pprime Sealing Workshop) and Sumy State University (16th International Scientific and Technical Conference «HERVICON+PUMPS-2020.
We have also found out that you carry through researches together with Korean colleagues. Could tell us something about the experience?
I continue carrying through joint researches with my Korean colleagues. Actually, in the 2018-2019 academic years, I had a one-year internship at the Korean Institute of Science and Technology in Seoul. It should be noted that this is the first research institute founded in South Korea, which in 2017 ranked 6th in the world among the top 25 global innovators according to the Thomson Reuters rating. According to the latest ranking, it ranks 13th in the world.
During this internship, I have participated in two projects on energy: «Development of Cryogenic Ball Bearing Technology for Liquefied Gas Pumps» and «Development of IoT-Based Turbogeneration Technology Using Unused Heat Sources» under the supervision of the Director of ROMIN Lab, Prof./Dr. Yong-Bok Lee. In the first project, I dealt with the two-phase medium flow and the bearing dynamics. In the second project, I supervised the impact of non-contact seals on the performance of the radial turbine, which is designed to generate electricity.
The results of these studies have already been presented at two conferences in South Korea. We are currently working on publishing the results of these works in top journals on mechanical engineering - the Mechanical Systems and Signal Processing and Energy (Elsevier).
It is known that you execute orders for the Ukrainian manufacturing industry. In particular, you’ve led applied studies for the Yuzhnoye Design Office. Could you describe this research in a few words?
Yes, in 2016-2017, we worked on a project for one of the world's most famous research and development companies to develop rocket and space technology, whose customers come from all corners of the world – from Europe, America, South Korea etc. The project‘s title is the «Study of rotordynamics of turbopump units of liquid rocket engines»; it was directly related to the analysis of rotordynamics on ball bearings, analysis of non-contact face impulse seal and axial balancing device, as well as the development of methods for the vibrational diagnostics of turbo pump units in liquid rocket engines. In fact, the seals and bearings have a significant impact on the vibrational state, thus on the reliability of the turbopump unit and the entire first stage of the launch vehicle. Therefore, this project was significant, and almost all of the teachers of our department have participated in it.
You have organized the famous international conference «HERVICON+PUMPS» What do you think about the way in which the topics under discussion within the framework of the conference influence the implementation of the applied scientific developments?
Let me answer this way. I am just one of the organizers of the event. We have a team of people (Dr.-Ing., Ass. Prof. Serhii Hudkov, PhD student Oleksandr Pozovnyi and others), who organize the international scientific and technical conference «Hermetic sealing, vibration reliability and environmental safety of pump and compressor equipment» ‒ «HERVICON+PUMPS». Vladimir Albinovich Marcynkowskyy also initiated this conference. It is held every three years since 1976. By the way, the 16th HERVICON+PUMPS-2020 conference was dedicated to the memory of Volodymyr Martsynkovsky and, as I said, was held online solely in English for the first time due to the COVID-19 quarantine. Participants from 7 countries discussed a total of 33 presentations and 19 poster presentations: from universities and research institutions of Ukraine, Poland, France, Slovakia, South Korea, China and Iraq.
Answering your question, I will say that the topics discussed at this conference are directly related to practical issues. We always invite to participate in our conferences not only scientists but also developers and consumers of pump and compressor equipment, bearings and seals. Therefore, scientists from both native and foreign universities can always find the necessary contacts and new customers to further implement their applied scientific developments in production or finished products. I want to add that the co-organizers of the conference are the leading machine-building companies of Ukraine and Sumy, i.e. JSC «Sumy plant «Nasosenergomash» and «TRIZ» Ltd with which our department actively cooperates. The conference articles are published in the Journal of Physics: Conference Series (JPCS) of IOP Publishing house (UK), which is accounted for by the Scopus and WoS scientific databases.
