Welcome to the Chair of Aerodynamics and Fluid Mechanics

Numerical modeling, simulation and experimental analysis of fluids and fluid flows

The focus of the Institute of Aerodynamics and Fluid Mechanics in 2016-17 was on further development of a multi-resolution parallel simulation environment for the NANOSHOCK project, on reduced-order modeling of fluid-structure interaction, on the analysis of advanced aerodynamic configurations for helicopter, aircraft and automobiles, and on advanced simulation and gridding technologies for exterior and interior aerodynamics.

A highlight in 2016-17 was the successful operation start of the large shock-tube  facility, and the kick-off of 2 interdisciplinary DFG projects with the Institutes IWB and FZG, where the Institute brings in its expertise on advanced flow-simulation methodology. Dr. Lin Fu, graduating from the Institute in 2017, received a Postdoctoral Fellowship of Stanford University,   and M.Sc. Thomas Paula received the Willy Messerschmitt award for his Master Thesis by the German Association for Aero- and Astronautics. Last but not least, from the NANOSHOCK project the first CFD code spin-off was opened for perusal by the scientific community: www.aer.mw.tum.de/abteilungen/nanoshock/news/.

Experimental and numerical investigation of cavitating two-phase flows and cavitation-induced erosion

Shock tube at AER-length 24 m, diameter 0.3 m, pressures from 1 Pa to 50 bar

Motivation and Objectives

The formation of vapor bubbles in a liquid due to pressure reduction is called “cavitation”. Flows involving cavitation feature a series of unique physical properties [1] such as discontinuous jumps in the speed of sound from O(1000) m/s to O(1) m/s, a jump in density of up to 4 orders in magnitude, and intense compressibility effects, such as the formation of intense shock-waves with post-shock pressures of more than 1GPa. Flows involving cavitation occur in a wide range of technical systems. In particular, injection systems for combustion engines, high pressure hydraulics, naval propellers and >> read more


Numerical methods for Computational Fluid Dynamics Physical consistency of high-resolution CFD

Instantaneous contours of temperature (top) of Ma=3 shock impinging on a turbulent boundary layer,and corresponding mean flow (bottom)

Motivation and Objectives

CFD tools in physical or engineering applications never can reach numerical resolution levels where the truncation error of the discretization schemes enters its asymptotic limit. It thus is of high practical relevance to design schemes that have good scale resolution properties whenever numerical resolution is sufficient for relevant flow scales, and whose truncation error functions as physically consistent subgrid-scale model when not. In the past, this research concept has led to the development of the first physically  >> read more


Smoothed Particle Hydrodynamics method for simulating free surface flow

Motivation and Objectives

Smoothed particle hydrodynamics (SPH) is a purely mesh-free Lagrangian method developed for astrophysical applications. Since these pioneering works, the SPH method has been successfully applied for numerical simulations of solid mechanics, fluid dynamics and fluid-structure interaction. Concerning the computation of hydrodynamic problems, the present methods either lead to violent pressure oscillations or excessive dissipation and are not able to reproduce correct physical phenomenon reliably. >> read more


Numerical modeling of Interface networks

Constant normal driven flow of an interface network with three regions at different time instance

Motivation and Objectives

Multi-region problems can occur when the motion of more than two immiscible fluids is to be described. In this case the interface network, separating the different fluid regions, evolves in time due to interactions of the different fluids across interface segments. These interactions often can be described by local fluid properties. Due to the complexity of the topology, numerical modeling the evolution and interactions near the interface network are long-standing challenges for the research community. >> read more


Aircraft and Helicopter Aerodynamics

Model of BLUECOPTER configuration mounted in the text section of wind tunnel A.

Motivation and Objectives

The long-term research agenda is based on the continues improvement of flow simulation and analysis capabilities in the context of aircraft and helicopter performance enhancement and drag reduction. Specific research activities are dedicated to the reliable prediction of flow separation onset and progression in the context of vortex dominated flow and control of leading edge vortex systems, development of a novel ROM framework for aeroelastic analysis, helicopter drag reduction of rotor hub and engine intake by shape optimization and flow control, development of propeller  >> read more


Modal Decomposition for Vehicle Aerodynamics

Iso-surfaces of the streamwise
velocity component of the most
dominant DMD mode at 9Hz

A new modal decomposition approach is employed for analyzing temporally resolved flow field data from Detached Eddy Simulation (DES) using the Open Source CFD environment OpenFOAM®. Velocity components are temporally filtered with moving average filter before being interpolated to a coarser equidistant mapping mesh. These filtering operations reduce the amount of spurious numerical oscillations in the data to be analyzed and cut off high frequency, low energy content. In order to extract the most dominant flow structures for in depth analysis, an incremental variant of Dynamic Mode Decomposition (DMD) was found to be most useful.  >> read more


Laminar-turbulent Transition with Chemical (Non-)Equilibrium in Hypersonic Boundary-Layer Flows

Computational setup for a roughness patch on a re-entry capsule

Motivation

Blunt bodies returning from space are subject to immense heat loads leading to ablation. Roughnesses on these ablating surfaces can induce laminar-turbulent transition in an otherwise laminar flow. Laminar-turbulent transition increases the heat load on the surface. This self-energizing effect can lead to a catastrophic failure of the spacecraft. The role of the chemical modelling in high-temperature boundary layers in equilibrium and non-equilibrium is the main focus of the numerical work.  >> read more


Our current research focuses are:

  • Aerodynamics of unconventional aircraft configurations
  • Aerodynamics of transport aircraft and high performance aircraft configurations
  • Future space transportation systems
  • Micro- and Nanofluidics
  • Turbulence modeling
  • Compressible turbulence
  • Two-phase flows
  • High Speed Aerodynamics