Hypersonics Research Capabilities At the University of Michigan Integrated Vehicle Analysis Cesnik, Driscoll, Friedmann Propulsion Driscoll, Gamba, Raman Aerodynamics Boyd, Gamba, Raman, Roe Materials Boyd, Sodano, Sundararaghavan Structures Cesnik, Friedmann Guidance, Navigation & Control Kolmanovsky, Cesnik
Hypersonic Aerodynamics Boyd, Gamba, Raman, Roe Computational Aerothermochemistry Turbulence Trajectory calculations on potential energy surfaces provide temperature dependent rates for CFD Quantum-to-continuum workflow and unsteady highly parallel solvers CFD Validation CFD Analysis of Vehicles Mach 20, 40 km altitude 11-species air Mach 12 flow tested at CUBRC, computed with UM hypersonic flow code LeMANS
Hypersonic Propulsion Driscoll, Gamba, Raman CFD capabilities Hypersonic facilities & diagnostics From ab-initio to continuum mechanics State-of-the-art combustion modeling, including complex detailed chemistry and non-equilibrium Rapid end-to-end simulations from CAD to results A combination of direct-connect ramjet/scramjet engine and high-enthalpy hypersonic facilities are used to access relevant conditions Dual-mode ramjet/scramjet studies Combustion modeling and complex geometry simulations Isolator studies Isolator performance, dynamics & control Cavity stabilized dual-mode studies Investigation of combustion properties and dynamics using modern laser diagnostics Direct numerical and large eddy simulations enable reducedorder modeling
Hypersonic Structures Cesnik, Friedmann Computational Aerothermoelasticity Aerothermoelastic Scaling Law Multi-fidelity computational framework for fluidstructuralthermal interaction Two-pronged approach: Analytical derivation + numerical simulation & optimization CFD-based transient simulation ROM-based quasi-steady simulation Deformation Temperature High-fidelity fully-coupled solution to reveal the mechanism of aerothermoelastic instability Novel ROM techniques and coupling schemes for faster-than-real-time simulation
Hypersonic Materials Boyd, Sodano, Sundararaghavan Thermal Protection Systems Ceramic Composites/Coatings Intact carbon fiber Partially oxidized fiber Tows Oxygen density distribution Effect of hypersonic flow on an ablating TPS Oxidation of Carbon Fiber in a Ceramic Matrix Composite Fabrication and Experimental Testing of TPS Multiscale modeling Ablation Resistant Tiles for Launch and Reentry Atomistic to continuum scale modeling for heat shield materials
Hypersonic Guidance, Navigation & Control Kolmanovsky, Cesnik Model predictive control guidance Real-time trajectory optimization for for time-optimal way way point point following subject to to exclusion zone, zone, actuator, structural and and thermal thermal constraints Constrained flight control Extended Command Governor (ECG) protects nominal closed-loop system against critical critical constraint violation x-y x-y trajectory, target target sets sets bank bank angle flight flight path path angle and and exclusion zones zones and and limits limits and and limits limits ECG ECG modifies set-points to to enforce constraints elastic deflections and and limits limits Real-time Simulation Control Design-oriented Modeling State State limits limits min(x,u), min(x,u), max(x,u) max(x,u) LHS LHS of x of x {x 1,,x {x 1,,x s,u 1,,u s,u 1,,u q } q } Surrogate Surrogate Training Training ID state ID state space space S S UΣV UΣV SVD SVD T T m-training m-training samples samples d d training training 0 th order 0 th order fit fit 1 st order 1 st order fit fit 2 nd 2order nd order fit fit Completed Completed ROM ROM yes yes no no Error Error tol. tol. d d testing testing UΣR UΣR T T k-testing k-testing samples samples NRMSE NRMSE Hardware-software integration for for RT RT simulation SVD SVD techniques to to create nonlinear fully fully coupled models for for control control design design
Integrated Hypersonic Airframe Scramjet Model for Aerothermoelastic Deformation Friedmann, Driscoll Integrated Vehicle-Scramjet Model Conjugate Heat Transfer (CHT) Cowl Integrated vehicle-engine flow path consists of: elongated forebody, isolator, combustor and exit nozzle Aerothermoelastic deformation of cowl governs thrust Integrated Engine Performance F x Simultaneous solution of Navier-Stokes equations and structural heat transfer on undeformed vehicle Uncertainty Quantification (UQ) of Performance MASIV: Michigan AFRL Scramjet In Vehicle Engine performance by MASIV: a 2D static solver for the mean flow path of the propulsion system Aerothermoelastic deformations interpolated to the propulsion analysis Thrust F X indicator of aerothermoelastic deformation of cowl on engine performance For constant mass flow the deflection of the cowl leading edge is dominant and changes performance by up to 20% Cowl deformation is more important than change in angle of attack; therefore control strategy plays a significant role for performance