arXiv subjects

AmirHossein Ghaemi

Publications and source records attributed to AmirHossein Ghaemi.

3 recordsLinked to original sources

arXiv2026

Physics-Structured Surrogate Modeling and Conformal Robust Multipoint Optimization for Glider Wing Design

Aerodynamic design using surrogate assistance can lower the cost of concept design. Point accuracy, however, is not enough to ensure that the optimizer does not exploit any part of space which is uncertain or with low confidence. In this work we develop a locked physics-structured surrogate and robust multi-point framework for the early-stage design of glider wings. The framework utilizes a dataset of 150,000 Tornado vortex lattice simulations, which provides 16 continuous targets for the aerodynamics, root loads, and flight dynamics. A five-member dual-head ensemble distinguishes between similarity-based aerodynamic inputs and the physical structure required for dimensional dynamics, while exact decoder recovers dimensional forces and root-load proxy values. Split-conformal prediction gives simultaneous intervals for the 14 optimization outputs, while at the same time a nearest-neighbor support score limits the extrapolation. The in-distribution test resulted in a mean NRMSE of 0.0223, while the structured out-of-distribution test resulted in 0.0595. The global joint 95% intervals covered 94.71% of points in distribution and support conditioned calibration gave 91.08% coverage under structured shift. Three-speed search examined 16,384 geometries and kept 2,998 feasible designs, 198 of which are nondominated designs. After freezing 20 wings, 60 Tornado simulations were conducted. The 60 simulations resulted in a mean NRMSE of 0.0228, coverage for 58 of 60 operating points, and hard feasibility success for all 60. For all 20 wings, all three objective upper bounds are conservative. The primary contribution of this paper is the combination of structured multi-output learning, simultaneous calibration, support aware robust Pareto search and locked post-selection simulations.

cs.NE↗

arXiv2025

Model Predictive and Reinforcement Learning Methods for Active Flow Control of an Airfoil with Dual-point Excitation of Plasma Actuators

This study investigates the effectiveness of Model Predictive Control (MPC) and Reinforcement Learning (RL) for active flow control over a NACA 4412 airfoil near static stall at Reynolds number 4*10^5. By systematically evaluating these strategies, the research addresses a critical gap in optimizing excitation frequency and improving response time in flow control. The work contributes to understanding RL adaptability and performance versus MPC in aerodynamic flow separation control. Numerical simulations of the Reynolds Averaged Navier-Stokes equations with the Scale-Adaptive Simulation turbulence model are used. Dielectric Barrier Discharge plasma actuators in dual-point excitation mode control flow separation. The study evaluates adaptive MPC, temporal difference RL (TDRL), and deep Q-learning (DQL) for optimizing excitation frequency and expediting stabilization. An integrated signal processing DQL approach is also examined. Adaptive MPC achieved Cl = 1.60 at 110 Hz but struggled near physical limits. RL optimized excitation frequencies, reaching Cl = 1.62 in under 2.5 s at 100 or 200 Hz. The study presents a novel RL - MPC comparison for active flow control with DBD actuators, contrasting with prior work focusing on MPC or RL alone. Using an online learning framework, RL methods dynamically adapt to real-time conditions. Evaluating adaptive MPC and RL together in this setup yields new insights into comparative performance in dynamic environments.

physics.flu-dyn↗

arXiv2025

Integrated Multiphysics Modeling of a Piezoelectric Micropump

This paper presents an integrated multiphysics simulation approach of piezoelectric micropumps. Micropumps and micro blowers are essential devices in various cutting-edge industries like laboratory equipment, medical devices, and fuel cells. A piezoelectric micropump involves complex physics including microfluidics, flow-structure interaction, electricity, and piezoelectric material. Hence, a comprehensive analysis of the interactions between different physical phenomena, would be essential for the effective design and optimization of these micropumps. Prior studies on piezoelectric micropump were mainly focused on isolated physical aspects of these pumps, such as piezoelectric mechanics, fluid dynamics, electrical properties, and also fluid-structure Interactions. The present paper fills this gap by integrating these aspects into a holistic simulation and design approach, introducing a new methodology for micropump analysis. Advanced simulation and design tools like COMSOL and SolidWorks were employed in accordance. A brief review of piezoelectric materials, and an exploration of different types of micropumps and their operating principles is discussed. Also, a comparison of various piezoelectric materials, including their properties and applications is investigated. Further, the paper discusses the simulation process of the micropumps, using COMSOL software, and presents an in-depth analysis of the simulation results. This structured approach provides a comprehensive understanding of piezoelectric micropumps, from theoretical underpinnings to practical design considerations. ..

physics.flu-dyn↗