Born: Japan
Primarily active in: United States of America

Daiju Uehara is a doctoral student in aerospace engineering at the University of Texas at Austin. He is a two-time winner of the Vertical Flight Foundation scholarship.

Growing up in Okinawa, Daiju was fascinated by the Black Hawks and other vertical flight aircraft that flew overhead to deliver emergency relief to the otherwise impassable terrain on the small southern Japanese island. Motivated to become a rotorcraft design engineer, he studied aerospace engineering at the University of Tokyo.

After graduating, Daiju decided to join Dr. Jayant Sirohi’s Aeroelasticity Lab to fulfill his passion for rotorcraft mechanics. He began by performing hover tests with a coaxial counter-rotating rotor (CCR) system and coaxial co-rotating system, comparing the results of each test to quantify how much energy the counter-rotating configuration was able to recover from the wake swirl compared to other rotor configurations. He presented the results at Forum 73 in his paper, “Quantification of Swirl Recovery in a Coaxial Rotor System.”

Daiju then embarked on a novel experimental technique to measure stiffness distribution and non-rotating natural frequencies of an extremely flexible rotor blade using a combined technique of digital image correlation and operational modal analysis algorithms. He presented the research outcomes in May in the paper, “Automated Operational Modal Identification of a Rotor Blade,” which was recognized as the best overall paper for the Dynamics Sessions papers at Forum 74.

 

Daiju is now testing a 6.6 ft (2-m) diameter model-scale coaxial counter-rotating rotor system to understand transient blade passage loads of a coaxial rotor; the findings will be presented at the upcoming 44th European Rotorcraft Forum in Delft, The Netherlands. His mentor Dr. Sirohi is proud of this progress: “Due to his dedication, hard work and attention to detail, Daiju has made significant contributions to his research area; he also spent a great deal of time learning the experimental techniques that he is now an expert in.” Daiju’s ultimate goal is to create an algorithm or experimental methodology to reconstruct the aerodynamic forces acting on helicopter blades from structural response data.

“Receiving the VFF scholarship [in 2017] as a MS student was the first great opportunity for me to be recognized in the rotorcraft community,” Daiju recounted. “The scholarship [in 2018] as a PhD student helped me a lot to apply to summer intern positions, and I was lucky enough to have an intern position at NASA’s Jet Propulsion Lab to work on numerical modeling of energy estimation of rotary VTOL planetary exploration [on Saturn’s moon Titan]. This is truly a dream-come-true moment for me and is one of the biggest impacts on my aerospace career.”

 

VFF Scholar Spotlight: Vertiflite September/October 2018