Biography:

Meinhard T Schobeiri full Professor of Mechanical Engineering Department, Texas A&M University since 1987 May. Dr Ing (PdD), 1978, Technical University Darmstadt, Germany, Department of Mechanical Engineering. Dipl Ing (MS), 1970, Technical University Darmstadt, Germany, Department of Mechanical Engineering. Dipl-Vorprufung (BS), 1967, Technical University Darmstadt, Germany, Department of Mechanical Engineering.

Abstract:

Gas turbines are engines within which the chemical energy of the fuel is converted either into mechanical energy for power generation or kinetic energy for producing propulsive force for aircraft . Th e conversion of the fuel energy into power or propulsive force requires an interaction of several components of the engine where aero-thermodynamic processes take place. Each process is associated with an entropy generation causing a depreciation in total pressure. As a result, the component effi ciency deterioration reduces the gas turbine thermal effi ciency. Th is, however, is the most important quantity for evaluating the overall aero-thermodynamics quality of the engine and is a measure for reducing the fuel consumption. High
thermal effi ciency not only reduces the fuel consumption but it also reduces the production of toxic exhaust emissions that are  threatening the health and integrity of the global environment. Th us, investigating the impact of the individual parameters on thermal effi ciency and its accurate prediction defi nes the framework of this talk. Th e presentation gives an overview of the gas turbine aerodynamics, performance and its dynamic behavior at the design and off -design operation conditions. A brief description of an ultra-high-effi ciency gas turbine concludes the talk.

Biography:

Ramesh K Agarwal received PhD from Stanford University in 1975 and post-doctoral training at NASA’s Ames Research Center in 1976. From 1976 to 1994, he was the Program Director and McDonnell Douglas Fellow at McDonnell Douglas Research Laboratories in St. Louis. From 1994 to 2001, he was the Sam Bloomfi eld Distinguished Professor and Executive Director of National Institute for Aviation Research at Wichita State University in Wichita, KS. He is currently the William Palm Professor of Engineering at Washington University in St. Louis. He is the author/co-author of nearly 250 archival papers and over 500 conference papers. He is on the editorial board of 20+ journals. He is a Fellow of eighteen societies including AIAA, ASME, ASEE, SAE, IEEE, APS and AAAS among others. He is the recipient of many honors and awards.

Abstract:

The Wing In Ground Eff ect (WIG) aircraft operates with larger lift to drag ratio compared to a conventional aircraft at low subsonic Mach numbers. To increase the traffi c volume of the WIG aircraft , one possible way is to increase the fl ight speed, which can result in transonic fl ow. Currently, the studies on the transonic fl ight in ground eff ect are very few. Th e focus of this paper is to study aerodynamics and fl ow physics of a typical transonic RAE2822 airfoil at Angles of Attack (AOA) from 0 to 12 deg. and Mach numbers from 0.5 to 0.8 in ground eff ect by varying the ground clearance above the ground. Th e compressible Reynolds-Averaged Navier-Stokes equations with Spalart-Allmaras (SA) turbulence model are solved using the commercial Contract for diff erence (CFD) solver ANSYS Fluent. For fl ight near the fl at ground surface, some interesting shock formations and fl ow phenomenon are obtained due to transonic fl ow. For the unsteady shock buff et phenomenon on the upper surface, the buff et boundary in the Angle of Attack (AOA) Mach number (Ma) plane shrinks with the decreasing ground clearance. Compared to the unbounded fl ow fi eld, there exists a steady shock on the lower surface of the airfoil in ground eff ect for low AOA’s because the channel between the lower surface of the supercritical airfoil and the ground is a typical convergingdiverging shape, resulting in the decrease in lift and increase in drag. For extreme conditions of very small ground clearance, small AOA and high Mach numbers, a new coupling between the shock buff ets on the lower and the upper surface of the airfoil is observed. Th e unsteady aerodynamics of transonic fl ow in the presence of a wavy ground is also analyzed.

Biography:

Hamid R Hamidzadeh received his PhD in Applied Mechanics from Imperial College where he also conducted postdoctoral research for four years. He is the Professor of Mechanical and Manufacturing Engineering Department at Tennessee State University. He is a Fellow of ASME and a Distinguished Member and Fellow of the SDPS. He has published three books and over 200 articles. He serves as Co-editor and Editorial Board Member for fi ve journals. He has organized major conferences and has served the ASME as chair of the Special Divisions Steering Committee, Conference Planning Committee, Executive Committee of Design Division and Vice-chair of the Board on Technical Knowledge Dissemination.

Abstract:

The presentation is to provide an overview of mathematical modeling and signifi cant results for a number of research projects
conducted by the speaker over the years on the areas of dynamics, vibrations and control of engineering systems. Topics include: Wave propagation in an elastic half-space medium, soil dynamics, soil-foundation interaction, vibrations of thick elastic cylindrical structures, control of vibration in thick cylindrical structures using constrained layer damping, nonlinear analysis of lateral vibration of high speed annular disks, in-plane vibrations of high speed annular disks, dynamical response of adhesively bonded beams, fl ow- induced vibration in pipes, stability of fl exible cam-follower systems, vibration of structures made of thin-fi lm membranes, system identifi cations, inverse dynamic model for lower extremities during gait and determination of crack in structures.

Biography:

Gustaaf Jacobs received a MSc in Aerospace Engineering from the Delft University of Technology in 1998, where after graduation, he was appointed to Research Associate. He received a PhD in Mechanical Engineering from the University of Illinois at Chicago. Following graduation in August of 2003, he was appointed Visiting
Assistant Professor in the Division of Applied Mathematics at Brown University. He later combined this position with a Postdoctoral Fellowship at the Department of Mechanical Engineering at the Massachusetts Institute of Technology. As of August 2006, he was appointed Assistant Professor of Aerospace Engineering at San Diego State University and was promoted to Associate Professor in August of 2010. He graduated with an Honor Propedeuse from the Delft University of Technology. In 2002 he was awarded a University Fellowship at the University of Illinois. He received an AFOSR Young Investigator Award in 2009 and became an Associate Fellow of the American Institute of Aeronautics and Astronautics in 2013. The research interests of his can broadly be defi ned in an area of computational multiphase and multi-scale fl ow physics using high-order methods. Particular emphasis is on simulation and analysis of particle-laden flows and flows separation in complex geometries and plasmas to aid fl ow control relating to combustion optimization and drag reduction.

Abstract:

Particle-laden fl ows have many scales ranging from the large-scale process scale up to the minute particle scale. Th is type of multiscale problems appears in several important engineering applications, e.g. the dynamics of particle-laden gases, deformation of heterogeneous materials such as bones, concrete, heterogeneous explosives, sediment transport in river beds and mesoscale models of blood fl ow. In such problems, computational approaches typically model unresolved or subgrid scales in an ad-hoc manner. Closure laws are obtained from physical experiments, canonical theoretical constructs or phenomenological arguments. In multiscale modeling, the macroscale is coupled with a mesoscale approach and closure laws are obtained from highly resolved mesoscale simulations. In this presentation, I will discuss multiscale modeling for particle-laden fl ows with shocks. Highly resolved mesoscale simulations of a shock interaction with a cloud of particles are discussed. Macroscale computations of the shock-fl uid problem are performed where a point particle assumption is used to model the particle phase. Th e linkage between scales is established through metamodels that assimilate mesoscale physics into surrogate models and serve as closure models for the macro-scale simulations.

Biography:

Danesh Tafti is the William S Cross Professor of Engineering at Virginia Tech. He obtained his PhD from the Penn State University and after post-doctoral studies at the University of Illinois at Urbana Champaign (UIUC) spent 10 years at the National Center for Supercomputing Applications at UIUC before joining Virginia Tech
in 2002. At Virginia Tech he directs the High Performance Computational Fluid Thermal Science and Engineering Lab. He has over 220 peer-reviewed journal and conference publications. He serves as the Associate Editor of the ASME J Heat Transfer and is a member of the Editorial Board of several journals.

Abstract:

Bats have highly dexterous and articulated membrane wings which can be manipulated by their hand digits during fl ight. Th is allows them to exert fi ne control over the shape and mechanical properties of the wing by fl exing their fi nger bones and changing the wing membrane stiff ness and shape. Many bat species are able to navigate and hunt in dense vegetation and can capture prey on the wing, oft en within very short time intervals and while operating in confi ned spaces. Challenges in studying bat fl ight include experimental data acquisition of wing kinematics and simulations of a highly deformable surface in space and time. An optical motion capture system of 21 cameras was used to mitigate wing self-occlusion while tracking 108 discrete marker points on the bat’s wings (Pratt's roundleaf bat, Hipposideros pratti) over the course of a meter-long fl ight. Th e surface of each wing is reconstructed in 3D space and time by the use of Proper Orthogonal Decomposition (POD) to fi lter noisy low energy modes of motion. Th e resulting kinematic model is interfaced with an unsteady incompressible fl ow
solver using the Immersed Boundary Method (IBM) and Large Eddy Simulation (LES) to characterize force production. To aid fundamental understanding, the complex wing kinematics is deconstructed into canonical descriptors of fl apping fl ight and related to aerodynamic force production.

Biography:

Abstract:

Soft electroactive materials can deform to a large extent in a reversible way under mechanical or electrical loading. This unique ability makes them very attractive to be the material candidates for designing smart and tunable devices, structures and systems. We will report some recent advances in tunable soft Phononic Crystals (PCs) in which waves can be manipulated according to the application purpose. In particular, attention will be paid to a simple one-dimensional soft PC cylinder made of dielectric elastomer. A series of mechanically negligible soft electrodes are placed periodically along the dielectric elastomer cylinder and hence the material is actually uniform in the undeformed state as well as in the uniformly pre-stretched state subjected to a static axial force only. Th e periodicity of the structure that is required for a PC is acquired via two diff erent loading paths. In the fi rst path, we fi x the longitudinal stretch and then apply an electric voltage over any two neighboring electrodes. In the second path, the axial force is kept unchanged and then the voltage is applied. Th e outstanding performance regarding the band gap (BG) property of the soft dielectric PC is well demonstrated through the comparison with the conventional design adopting the hard piezoelectric material. We also illustrate that the snap-through instability of the axially free PC cylinder made of a generalized Gent material may be used to trigger a sharp transition in the BGs.

Biography:

Dean Vucinic joined Vesalius College (VeCo) in 2017 as the senior scientifi c advisor and he is continuously affi liated to Vrije University Brussel from 1988. Before joining VeCo, he was the Guest Professor and Senior Research Scientist at the VUB Faculty Of Engineering Sciences being the member of its 2 departments: Mechanical Engineering and Electronics & Informatics. He is also the part-time Associate Professor at the Faculty of Electrical Engineering, Computer Science and Information Technology, University of Osijek, holding the chair of visual computing. His work is mostly related to research and development projects and his interest covers the topics of scientifi c visualization, modeling and simulation, optimization methodologies and techniques, which are very often found together in solving complex problems within the multidisciplinary engineering and computer science domains. His PhD thesis became a book in 2010, ISBN 978-3-8383-3500-1. In early 90's he developed "CFView- Computational Field Visualization System", fi rst-time-ever interactive visualization software adapted to numerical simulation solvers, completely based on the object-oriented technology and fully implemented in C++. During almost 30 years at VUB, he successfully participated in more than 20 European projects under the European frameworks, EUREKA/ITEA and Tempus educational programs. He is an author of more than 60 scientifi c papers in the international reviewed journals and conferences proceedings. He is the European Commission Expert in H2020 and member of the following international organizations: AIAA, IEEE, ACM, SAE & ASME.

Abstract:

The modeling and visualization aspects underpinning the analysis of the numerical simulation data of the bidirectional Fluid-Structure Interaction (FSI) characterizing the human heartbeat are discussed in details. Th is approach involves the general-purpose Computational Fluid Dynamics (CFD) FlowVision code and the SIMULIA Living Heart Human Model (LHHM). LHHM is a dynamic, anatomically realistic, 4-chamber heart model having 2 mechanical valves, which couples the multiphysics electrical and mechanical fi elds acting during the heartbeat. Th eir synchronous actions regulate the heart fi lling, ejection and overall pump functions. Originally, LHHM comes with a 1D fl uid network model, only capable of simulating the dynamic pressure/volume changes of the intra and extra-cardiac circulation network model. A full 3D blood circulation is numerically modeled with FlowVision, which makes possible to apply a very detailed spatial and temporal resolution for modeling the cardiac hemodynamics, together with its time-varying boundary conditions of the heartbeat. In order to validate such an approach, the bidirectional coupling between the Flow Vision blood fl ow model (CFD) and the LHHM model (FEM) is integrated with the SIMULIA co-simulation engine. Th e performed numerical modeling and simulations of the human heartbeat, as fl uid-structure interaction multiphysics phenomena are further analyses and discussed, together with the envisaged potential applications of such coupled modeling and simulation approach. Th us, especially interesting when the device interactions are necessary to be upfront considered to correctly predict their infl uence in the heart diseases treatment. Finally, it is concluded that such complex multiphysics heartbeat simulations data analysis requires advanced modeling and
visualization techniques to achieve the multidisciplinary integration of 3D electrical, structural and fl uid numerical models, expected to move this technology towards more realistic simulations of the cardiac mechanisms and thus, create new ways to treat cardiovascular disease in the future.

Biography:

Danila Prikazchikov has received his PhD from the University of Salford, UK. After working for several years as an Associate Professor at Bauman State Technical University, Moscow, he moved to Keele University, UK in 2013. He has co-authored around 50 publications, including a recent substantial chapter in “Advances in Applied Mechanics”. His awards and honors include two Russian Presidential Fellowships for Young Scientists, along with visiting positions at City University of Hong-Kong and Anadolu University.

Abstract:

The lowest vibration modes of high-contrast elastic multi-component structures are discussed. Examples of such structures appear in various areas of modern engineering, including, in particular, layered structures, e.g. photovoltaic panels and laminated glass, see and references therein. Other prospective areas involve energy harvesting and robotics. Th e consideration starts from problems for elastic multi-component rods and membranes, which possess the fi rst non-zero natural frequency tending to zero due to high contrast in material and geometrical parameters of the components. Th e approach relies on the concept of an “almost rigid body motion”, performed by the stronger components subject to homogeneous Neumann type boundary conditions. A perturbation procedure provides both estimates for frequencies satisfying a polynomial equation of order equal to the number of stiff components, along with piecewise polynomial approximations for the eigenforms. Then, the analysis is extended to antiplane motions of layered waveguides and also of multi-layered cylindrical bodies of arbitrary cross section. Next, we consider problems of elasticity for layered structures, focussing on antisymmetric motion of a threelayered strongly inhomogeneous sandwich plate. Th e previous results for rods correspond to the phenomena of the lowest first
shear cut-off frequency tending to zero, thus opening the room for two-mode low-frequency approximate theories for bending of high-contrast sandwich plates. Several practically important setups are considered, demonstrating the possibility of both uniform and non-uniform asymptotic approximations, leading to two distinct types of the governing plate equations.