United States of America
1975 - 2011
Dr. Gaurav Gopalan was a young, prolific contributor to the American Helicopter Society and researcher at the Alfred E. Gessow Rotorcraft Center at the University of Maryland.
Dr. Gopalan was an Assistant Research Scientist in the Department of Aerospace Engineering and worked with Professor Fredric Schmitz in the field of helicopter acoustics. He was known and loved in multiple communities. A passionate thespian, he was also an active member of the Washington Shakespeare Company, where he served as an assistant director and stage manager. Dr. Gopalan was also president of his own consulting business.
He was born in New Delhi, India on December 6, 1975. An outstanding student, he graduated from the Indian Institute of Technology, in Kanpur India. After his graduation in 1998, he won a fellowship in the Aerospace Department at the University of Maryland and moved across the globe to the Washington DC area to obtain his graduate education. Gaurav firmly believed that America was the place for him to begin his career because he felt that the United States free enterprise system recognized hard work, innovation, talent, and enterprise. Working as a research assistant in the Alfred Gessow Rotorcraft Center over the next several years, he earned his Masters and Ph.D. degrees, specializing in the field of rotorcraft acoustics. He received many awards and scholarships and maintained a 4.0 GPA throughout his graduate education. He was a key founding member of a then recently established research group that was led by Professor Schmitz.
Dr. Gopalan was immediately drawn to the challenges of reducing helicopter external noise, and especially enjoyed the theoretical aspects of the research work that combined the fundamentals of helicopter acoustics and optimization techniques with practical aspects of helicopter performance. One goal of the research that he chose to work on was to explore new ways for helicopter pilots to “fly quietly” so they could minimize the noise to nearby communities. His Masters and Ph.D. theses developed a new theoretical method to predict the noise radiation of a helicopter in accelerating/decelerating flight. This new analysis resulted in significant modifications to the classical methods of ground noise map estimation used by both the rotorcraft industry and Department of Defense. His findings were presented to industry at AHS technical forums and specialists’ meetings and in technical journals. NASA also incorporated this new modeling procedure, as an option, in their existing Rotor Noise Modeling (RNM) code that predicts helicopter external noise radiation.
In his early days at the University of Maryland, Dr. Gopalan’s enthusiasm affected everyone around him. As he often commented, research at the fundamental level was fun because it was a challenging puzzle that needed to be unraveled and explored. No one knows the answers to Mother Nature’s secrets– but he believed that by working hard and using his God-given observation skills, he could be among the first to unravel her secrets.
Because of his capabilities and interest, Dr. Gopalan was offered a postdoctoral position at the University of Maryland. In that role, he assisted in teaching graduate-level courses in acoustics. He was an excellent teacher, patiently explaining difficult concepts with an innate understanding of the student’s point of view. He was also demanding, keeping the learning goals at high levels, so that the students would leave Maryland with a solid knowledge of rotorcraft acoustics. In addition to teaching, he also broadened his research work to be applicable for community noise planning purposes and co-authored several articles on this subject with other Maryland faculty and researchers.
Dr. Gopalan’s love of theory led him to develop a new theoretical expansion technique for rotor noise prediction that brought out the physics of blade design. His new theory makes the noise and performance tradeoffs among classic design parameters clearer – thus enabling more complete understanding of the process of “blade design for low noise.” This is helping blade designers develop quieter helicopter rotors. Dr. Gopalan’s new theory has also helped to set the stage for the pioneering work on anti-noise theory through on-blade control. This new theory, developed by Schmitz and Gopalan, focuses on reducing in-plane helicopter harmonic noise which is particularly important in determining a helicopter’s likelihood of detection. For several years, it had been theorized that this type of helicopter noise could be reduced by having the helicopter blades themselves radiate additional sound waves that would cancel those produced by the rotor. Early development was hindered by the complex nature of the governing mathematical relationships and it was not until Dr. Gopalan’s new theory was formulated that the missing link was found. His approach has paved the way for additional theoretical and experimental work. These experiments are already underway, with confirmed rotor noise reductions in both the 40-by-80 ft wind tunnel at NASA Ames using flaps and ongoing model scale experimental work at the University of Maryland. In his last days, Gaurav was guiding and assisting a doctoral student with key experimental research that helped validate the theory for on-blade anti-noise blowing controllers, a direct derivative of Gaurav’s theoretical analysis. As in any experiment, the experimental problems were often daunting. However, Dr. Gopalan’s ever-present leadership skills and positive attitude resulted in a unique set of experimental data that were reported at the 2011 AHS Annual Forum. As the good news of this experiment unfolded, it was apparent that it was one of the happiest and most professionally fulfilling times in Gaurav’s far too short life.
AHS Updates: Vertiflite Winter 2011