ayapilla.asp "AT" scrc.iir.isct.ac.jp
ayapilla.aditya.sai.pranith.t "AT" alumni.tohoku.ac.jp
pranith.aditya "AT" gmail.com
Brief intro... I’m Pranith, a postdoctoral researcher at the Institute of Science Tokyo (Onishi Laboratory). In plain language, I use computers and math to try to understand the physics of how fluids flow. But more formally, my work sits in the intersection of fluid dynamics and scientific machine learning, with current interests in ML-based numerical weather prediction, data assimilation and urban micrometeorology.
Quick background... I was born in Visakhapatnam (Vizag), a coastal city on the east coast of India. I completed my undergraduate studies in Mechanical and Aerospace Engineering at IIT Hyderabad (2020), and then moved to Sendai, Japan, for graduate studies at Tohoku University under Prof. Yuji Hattori, supported by a fully funded JICA scholarship. I received my PhD from Tohoku University in 2025.
Current research motivation... Over the past few centuries, scientists have developed a deep understanding of the physical world using three main approaches: experiments, theoretical analysis, and computer simulations. In recent years, advances in artificial intelligence (AI) have begun to influence many scientific fields, including fluid mechanics, which is central to problems such as weather prediction, aerospace engineering, and environmental sustainability. Many fluid dynamical systems, especially atmospheric flows, are highly complex, involving interactions across multiple scales and often exhibiting chaotic behavior. Because of this complexity, theoretical analysis is often difficult and high-fidelity numerical simulations can be extremely computationally expensive, making real-time prediction challenging. This is precisely where AI, in the form of scientific machine learning (SciML), has been time and again shown to be very useful. SciML can learn from expensive high-resolution simulations and later reconstruct high-resolution fields much faster from cheaper low-fidelity information.
My current line of research focuses on urban micrometeorology, which refers to weather behavior at the scale of cities and neighborhoods. I 'm working to combine methods of deep learning, generative AI, etc. with my background in fluid physics to develop computationally efficient, data-driven models that enable fast and accurate urban micrometeorological modeling and prediction. This is becoming increasingly important as rapid urbanization and climate change lead to weather patterns in cities that differ significantly from those in surrounding regions.
Previous work... Before my current work, in my PhD research, under the supervision of Hattori-sensei, I explored a more classical fluid-dynamics problem with more of a first-principled approach: a specific type of instability called the triangular instability, which can cause strained vortices to become unstable. Using theoretical analysis and numerical simulations, I showed that this instability can arise in Batchelor vortices (a widely used model for vortices in wake flows), and elucidated its characteristics, with potential relevance to the modeling and control of wind-turbine wakes.
Click here for a more detailed overview of my research experience and interests.
Click here for my curriculum vitae.
Profile and social links: Google Scholar, ResearchGate, LinkedIn.
The codes I developed/contributed to can be found on my Github.
04/2026: preprint. Our paper - Aditya Sai Pranith Ayapilla, Kazuya Miyashita, Yuki Yasuda, Ryo Onishi 2026 "Uncertainty-Aware Spatiotemporal Super-Resolution Data Assimilation with Diffusion Models" is now available as a preprint: https://arxiv.org/abs/2604.21180
04/2026: conference. Our talk titled "Diffusion-Model-Based Probabilistic Spatiotemporal Super-Resolution Data Assimilation of Geophysical Fluid Flows" is accepted as an oral presentation at ICCFD13, scheduled to take place 6–10 July 2026 in Milan, Italy. Authors: Aditya Sai Pranith Ayapilla, Kazuya Miyashita, Yuki Yasuda, Ryo Onishi.
03/2026: publication. Ayapilla, A.S.P., Hattori, Y. & Le Dize`s, S. 2026 "Triangular instability of a strained Batchelor vortex" is published in Journal of Fluid Mechanics. https://doi.org/10.1017/jfm.2026.11229 . Please see the preprint (https://arxiv.org/abs/2506.14717) if the main paper is locked behind paywall.
01/2026: Our paper - Ayapilla, A.S.P., Hattori, Y. & Le Dize`s, S. 2025 "Triangular instability of a strained Batchelor vortex" is accepted for publication in Journal of Fluid Mechanics.
10/2025: conference. Poster presentation at RIMS Seminar “Energy dissipation rate in turbulence” held at Awaji island, Japan from Oct 28-30, 2025. Poster title: “Triangular Instability of Strained Vortices: Linear Stability Analysis and Nonlinear Dynamics”
10/2025: Started working as a postdoctoral researcher in Onishi lab, Institute of Science Tokyo.
07/2025: publication. Our paper - Ayapilla, A.S.P., Hattori, Y. & Le Dize`s, S. 2025 "Triangular instability of a strained Lamb-Oseen vortex" is published in vol 1016 of Journal of Fluid Mechanics. https://doi.org/10.1017/jfm.2025.10409
07/2025: Successfully defended my PhD thesis, Theoretical and Numerical Studies on Triangular Instability of Strained Vortices in Incompressible Flows, under the supervision of Prof. Yuji Hattori. Thesis committee: Prof. Satoru Yamamoto (GSIS, Tohoku University), Prof. Naofumi Ohnishi (Department of Aerospace Engineering, Tohoku University), and Dr. Stephane Le Dizès (IRPHE).
06/2025: Gave a talk titled "Theoretical and Numerical Studies on Triangular Instability of Strained Vortices in Incompressible Flows." at Onishi laboratory at Institute of Science Tokyo, Ookayama campus.
06/2025: Our paper - Ayapilla, A.S.P., Hattori, Y. & Le Dize`s, S. 2025 "Triangular instability of a strained Lamb-Oseen vortex" is accepted for publication in Journal of Fluid Mechanics.
06/2025: preprint. Our paper - Ayapilla, A.S.P., Hattori, Y. & Le Dize`s, S. 2025 "Triangular instability of a strained Batchelor vortex" - is available as a preprint on arxiv.org: https://arxiv.org/abs/2506.14717
11/2024: conference. I presented my work "Tripolar Instability of a Strained Lamb-Oseen Vortex" at DFD-Interact during the APS DFD 2024 conference in Salt Lake City, Utah, USA.
08/2024: I visited Institut de Recherche sur les Phenomenes Hors Equilibre (IRPHE) at Marseille, France from July 2 to August 3 in 2024 to work with Stéphane Le Dizès. The IFS-GCORE Overseas Dispatch Program Grant provided the majority of the funding for this research trip.