Pipe Research On Boundary Effects and Scaling of probes EuHIT Funded Project

Team

Gabriele Bellani
university of bologna, Forlì, Italy
Tommaso Fiorini
Università di Bologna, Forlì, Italy
Peter A. Monkewitz
Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland
Hassan M. Nagib
IIT, Chicago, United States
Philipp Schlatter
KTH Stockholm, Stockholm, Sweden
Alessandro Talamelli
University of Bologna, Forlì, Italy
Ricardo Vinuesa Motilva
KTH, Stockholm, Sweden

Overview

Research Infrastructure
Center for International Cooperation in Long Pipe Experiments, Italy
Facilities used
Long Pipe Facility (LP)
Project leader
Arne Johansson
Royal Institute of Technology (KTH), Stockholm, Sweden

Abstract

Knowledge about near-wall behavior of turbulent flows at very high Reynolds numbers (Re) is crucial for many important applications in aeronautics and energy technology, but cannot be acquired by numerical simulations in the near future. So far, the highest Reynolds number experimental turbulence data from a laboratory have been obtained in a single facility, the pressurized Princeton Superpipe, with the NSTAP micro-probe of unusual design. These data do not extend the trends for turbulence intensity observed in the many lower Reynolds number facilities. In particular, the existence of a region governed by a power-law description below the logarithmic region, the values of the log law coefficients, a Re-independent inner peak of the streamwise velocity fluctuations, and the emergence of a Re-dependent outer peak contradict classical knowledge of wall-bounded turbulence. The question is whether these new observations are the manifestations of new physics at very high Re or whether they represent facility/probe effects. In this project we propose to analyze the effect of the NSTAP probe geometry on the turbulent flow, including blockage effects and upstream influence of the delta-wing shape. To this end, we will manufacture identical probes, scaled up by a factor of 6.5, and perform experiments in CICLoPE over a significant Re range to assess possible geometrical effects on the measurements.