Objectives

  • To study the influence of the sidewalls on the heat flux transport
  • To investigate the global and local heat flux transport for different aspect ratios
  • To verify different assumptions and predictions of the theoretical models for the velocity field
  • To study in details the boundary layers
  • To measure the dissipation rate and transport parameters, angular momentum flux and torque scaling for co- and counter rotation
  • To investigate the coherent turbulent structures using optical measurements
  • To study the statistical analysis of fully developed turbulence
  • Using the present simulations we aim to explore the emergence of the torque maximum for moderate counter-rotation and intermediate Reynolds numbers.
  • We plan to perform simulations to study the angular velocity current for a radius ratio of 0.5 which is currently investigated experimentally at the BTU Cottbus.
  • This enables further comparisons between numerical and experimental observations and may provide insights to the radius ratio dependence of the characteristics of the current.
  • To conduct measurements of the turbulent velocity fluctuations and pressure transients and to construct profiles of Reynolds stresses and their anisotropies within puff, splitting puff and slug structures, and the probability, lifetime, propagation speeds of those transitional structures.
  • To investigate the generation of TW of different types in the low Re range by the selection of proper disturbance parameters with the help of optimization algorithms. This study reveals the border between stable laminar states of the flow and the chaotic turbulent states of the flow, and the connection between the disturbance and the shapes of TW. As a result, each type can be generated reproducibly and studied separately. Ultimately, the path toward transition can be better described.
  • To investigate the velocity field and its statistics within the transitional structures, especially in TW, in order to establish the connection between findings made for laminar TW structures and for the turbulent puff and slug structures.
  • To find out the similarities between the observed flow structure in PF, and RB and TC flows on the basis of turbulent stress profiles, their path on the AI-map, probability and lifetime statistics.
  • To perform numerical simulations at medium and low Reynolds numbers and to clarify the discrepancy between the theory and experiment mentioned at State-of-Art.
  • To identify the phase space structures at Reynolds number around 1800
  • To investigate the stability properties of travelling-wave-type-solutions in pipe Poiseuille flow
  • To identify the global bifurcations, to characterize the behaviour near the critical point
  • To develop methods to stabilize travelling waves
  • To develop reduced models of pipe flows