Sang-Jun Shin

Within the framework of blade aerodynamic design, the maximum aerodynamic efficiency, power production, and minimum thrust force are the targets to obtain. This paper describes an improved optimization framework for blade aerodynamic design under realistic conditions, while considering multiple design parameters. The relationship between the objective function and the design parameters, such as the chord length, maximum chord, and twist angle, were obtained by using the second-order response sur

An improved data-driven non-intrusive model order reduction (MOR) methodology capable of interpolating time-transient flow-fields and other types of data with respect to the parameters is proposed. The proposed MOR method comprises the following two stages: MOR and interpolation. For the MOR, modified proper orthogonal decomposition (POD) is used to collect the parametrically independent POD modes and dependent coefficients. An interpolation of the POD coefficients is conducted through unsupervi

Recently, there has been an increase in the research on flapping wing vehicles which mimic biological motions. One result has been the flapping wing micro-aerial vehicle. In this paper, the design requirements for flapping wing micro-aerial vehicles were established through an analysis with the unsteady blade element theory. Then, based on the flapping wing micro-aerial vehicle design requirements, a flapping wing mechanism using a pair of six-bar linkage was devised. Moreover, several candidate

Abstract An improved nonintrusive parametric model order reduction (pMOR) approach is proposed for the flow field interpolation regarding fluid–structure interaction (FSI) objects. Flow field computation using computational fluid dynamics (CFD) requires excessive computational time and memory. Nonintrusive and data-driven MOR schemes have been proposed to overcome such limitations. The present methodology is implemented by both proper orthogonal decomposition (POD) and a modified Nouveau variati

This paper presents the design process and experimental results of a brand new flapping and trailing edge control mechanism for a flapping wing micro air vehicle. The flapping mechanism, whose main components are fabricated from string, is suggested and optimized further by a modified pattern search method. The trailing edge control mechanisms for pitching and rolling moments are designed to be attached onto the present flapping mechanism in a modularized fashion. Prototypes of both mechanisms a

An Active Twist Rotor (ATR) is developed for future implementation of the individual blade control for vibration and noise reduction in helicopters.The rotor blade is integrally twisted by direct strain actuation using active fiber composites (AFC).In order to design and analyze an active blade, a general framework is proposed.A multi-cell thin-walled active composite beam model is developed.The model is validated against a combination of other theoretical models and experimental data.Actuation

Unmanned aerial vehicles (UAVs) are widely used, particularly in urban environments. However, existing studies on multi-rotor UAVs have rarely attempted simulations or experiments considering the significant intensity of gust induced by buildings. This study develops an improved real-time flight simulation for predicting the transient response of a multi-rotor UAV influenced by gust. The unsteady rotor aerodynamics which is appropriate to be implemented in the flight simulation is coupled with t

Flapping wing micro-air vehicles are biologically inspired by nature flyers, specifically insects and birds. Specifically, insect wings generally consist of veins and membrane components. In this study, a structural analysis considering the vein/membrane components of an insect-like flapping wing is presented. Co-rotational (CR) finite elements are adopted in order to consider the complex wing configuration including both vein and membrane. The CR beam elements with warping degrees of freedom ar