Microfluidics and Nanofluidics

, Volume 11, Issue 6, pp 773–780

Microflow-based control of near-wall fluctuations for large viscous drag reduction

Authors

    • Institute of Fluid MechanicsFriedrich-Alexander University Erlangen-Nuremberg
    • Center of Smart InterfacesTechnische Universität Darmstadt
  • Bettina Frohnapfel
    • Center of Smart InterfacesTechnische Universität Darmstadt
  • Rubitha Srikantharajah
    • Institute of Fluid MechanicsFriedrich-Alexander University Erlangen-Nuremberg
  • Djordje Jovanović
    • Institute of Fluid MechanicsFriedrich-Alexander University Erlangen-Nuremberg
  • Hermann Lienhart
    • Institute of Fluid MechanicsFriedrich-Alexander University Erlangen-Nuremberg
  • Antonio Delgado
    • Institute of Fluid MechanicsFriedrich-Alexander University Erlangen-Nuremberg
Research Paper

DOI: 10.1007/s10404-011-0842-1

Cite this article as:
Jovanović, J., Frohnapfel, B., Srikantharajah, R. et al. Microfluid Nanofluid (2011) 11: 773. doi:10.1007/s10404-011-0842-1

Abstract

The stabilizing effect of microgroove surface morphology on viscous drag reduction was studied experimentally in the inlet region of a plane channel flow. The stabilization is thought to be due to the ability of a microgrooved surface pattern to suppress the velocity fluctuations in the spanwise direction on a restricted portion of the wetted surface, which prevents vorticity development at the wall and consequently across the entire flow field. This smart microflow control strategy, which works successfully only under very particular circumstances, was implemented in a microgroove-modified channel flow in which the front part has a microgrooved surface topology. The results of pressure drop measurements indicate that microgrooved surfaces can effectively stabilize laminar boundary layer development, leading to a significant reduction in the viscous drag. In the rear flat part of the microgroove-modified channel test section, a maximum drag reduction of \({\rm DR\simeq 35\%}\) was measured. This corresponds to an overall drag reduction of \({\rm DR\simeq 16\%}\) at a length Reynolds number of \(Re_x\simeq 10^6. \) The drag reduction effect persisted in a narrow range of flow velocities and for the reported experimental conditions corresponds to microgroove dimensions between 1.5 and 2.5 viscous length-scales.

Copyright information

© Springer-Verlag 2011