On the role of pressure in elasto-inertial turbulence

The dynamics of elasto-inertial turbulence is investigated numerically from the perspective of the coupling between polymer dynamics and flow structures. In particular, direct numerical simulations of channel flow with Reynolds numbers ranging from 1000 to 6000 are used to study the formation and dynamics of elastic instabilities and their effects on the flow. Based on the splitting of the pressure into inertial and polymeric contributions, it is shown that the polymeric pressure is a non-negligible component of the total pressure fluctuations, although the rapid inertial part dominates. Unlike Newtonian flows, the slow inertial part is almost negligible in elasto-inertial turbulence. Statistics on the different terms of the Reynolds stress transport equation also illustrate the energy transfers between polymers and turbulence and the redistributive role of pressure. Finally, the trains of cylindrical structures around sheets of high polymer extension that are characteristics of elasto-inertial turbulence are shown to be correlated with the polymeric pressure fluctuations

Polymer Maximum Drag Reduction: A Unique Transitional State

The upper bound of polymer drag reduction is identified as a unique transitional state between laminar and turbulent flow corresponding to the onset of the nonlinear breakdown of flow instabilities

Radiation Modeling of a Hydrogen-Fueled Scramjet

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90696/1/AIAA-2011-3769-521.pd

Full-system RANS of the HyShot II scramjet Part 1: Numerics and non-reactive simulations

Predictive Science Academic Alliance Program (PSAAP

Higher Fidelity Transonic Aerodynamic Modeling in Preliminary Aircraft Design

editorial reviewedThere is a consensus in the aerospace research community that future aircraft will be more flex- ible and their wings will be more highly loaded. While this development is likely to increase air- craft efficiency, it poses several aeroelastic ques- tions. Current aeroelastic tailoring practice for early preliminary aircraft design relies on linear aerodynamic modeling, which is unable to pre- dict shocks and boundary layers. The objective of this research is to enhance the linear aerodynamic modeling methodology, thus allowing fast and re- liable aerodynamic loads prediction for aeroelas- tic computations. First, the different levels of fi- delity of aerodynamic modeling that can be used in aircraft design are reviewed and compared on benchmark test cases. A Field Panel Method is subsequently developed and implemented. Pre- liminary results are presented and possible future enhancements are detailed

On some drawbacks and possible improvements of a lagrangian finite element approach for simulating incompressible flows

In this paper a Lagrangian finite element approach for the simulation of incompressible flows is presented, based on the so-called Particle Finite Element Method (PFEM). The spatial discretization and the definition of the boundary terms are discussed in detail with a specific focus on free-surface flows. Additionally, some problems that can arise from the use of such a method are pointed out. Some numerical examples are given and discussed in the last section of the paper