Skip to main content Accessibility help

Bubble-induced skin-friction drag reduction and the abrupt transition to air-layer drag reduction



To investigate the phenomena of skin-friction drag reduction in a turbulent boundary layer (TBL) at large scales and high Reynolds numbers, a set of experiments has been conducted at the US Navy's William B. Morgan Large Cavitation Channel (LCC). Drag reduction was achieved by injecting gas (air) from a line source through the wall of a nearly zero-pressure-gradient TBL that formed on a flat-plate test model that was either hydraulically smooth or fully rough. Two distinct drag-reduction phenomena were investigated; bubble drag reduction (BDR) and air-layer drag reduction (ALDR).

The streamwise distribution of skin-friction drag reduction was monitored with six skin-friction balances at downstream-distance-based Reynolds numbers to 220 million and at test speeds to 20.0ms−1. Near-wall bulk void fraction was measured at twelve streamwise locations with impedance probes, and near-wall (0 < Y < 5mm) bubble populations were estimated with a bubble imaging system. The instrument suite was used to investigate the scaling of BDR and the requirements necessary to achieve ALDR.

Results from the BDR experiments indicate that: significant drag reduction (>25%) is limited to the first few metres downstream of injection; marginal improvement was possible with a porous-plate versus an open-slot injector design; BDR has negligible sensitivity to surface tension; bubble size is independent of surface tension downstream of injection; BDR is insensitive to boundary-layer thickness at the injection location; and no synergetic effect is observed with compound injection. Using these data, previous BDR scaling methods are investigated, but data collapse is observed only with the ‘initial zone’ scaling, which provides little information on downstream persistence of BDR.

ALDR was investigated with a series of experiments that included a slow increase in the volumetric flux of air injected at free-stream speeds to 15.3ms−1. These results indicated that there are three distinct regions associated with drag reduction with air injection: Region I, BDR; Region II, transition between BDR and ALDR; and Region III, ALDR. In addition, once ALDR was established: friction drag reduction in excess of 80% was observed over the entire smooth model for speeds to 15.3ms−1; the critical volumetric flux of air required to achieve ALDR was observed to be approximately proportional to the square of the free-stream speed; slightly higher injection rates were required for ALDR if the surface tension was decreased; stable air layers were formed at free-stream speeds to 12.5ms−1 with the surface fully roughened (though approximately 50% greater volumetric air flux was required); and ALDR was sensitive to the inflow conditions. The sensitivity to the inflow conditions can be mitigated by employing a small faired step (10mm height in the experiment) that helps to create a fixed separation line.



Hide All
Bodgevich, V. G. & Evseev, A. R. 1976 The distribution of skin friction in a turbulent boundary layer of water beyond the location of gas injection. Investigations of Boundary Layer Control (in Russian), vol. 62. Thermophysics Institute Publishing House.
van den Berg, T. H., Luther, S., Lathrop, D. P. & Lohse, D. 2005 Drag reduction in bubbly Taylor–Couette turbulence. Phys. Rev. Lett. 94, 044501.
Ceccio, S. L. & George, D. L. 1996 A review of electrical impedance techniques for the Trans. ASME I: measurement of multiphase flows. Trans. ASME: I J. Fluids Engng 118, 391399.
Cho, J., Perlin, M. & Ceccio, S. L. 2005 Measurement of near-wall stratified bubbly flows using electrical impedance. Meas. Sci. Technol. 16, 10211029.
Clark, H. & Deutsch, S. 1991 Microbubble skin friction reduction on an axisymmetric body under the influence of applied axial pressure gradients. Phys. Fluids A 3, 29482954.
Deutsch, S., Money, M., Fontaine, A. & Petrie, H. 2003 Microbubble drag reduction in rough walled turbulent boundary layers. Proc. ASME–Fluids Engng Div. Summer Meeting 2003, pp. 19.
Druzhinin, O. A. & Elghobashi, S. 1998 Direct numerical simulations of bubble-laden turbulent flows using two-fluid formulation. Phys. Fluids 10, 685697.
Etter, R. J., Cutbirth, J. M., Ceccio, S. L., Dowling, D. R. & Perlin, M. 2005 High Reynolds number experimentation in the US Navy's William B. Morgan large cavitation channel. Meas. Sci. Technol. 16 (9), 17011709.
Fontaine, A. A. & Deutsch, S. 1992 The influence of the type of gas on the reduction of skin friction drag by microbubble injection. Exps. Fluids 13, 128136.
George, D. L., Iyer, C. O. & Ceccio, S. L. 2000 Measurement of the bubbly flow beneath partial attached cavities using electrical impedance probes. Trans. ASME I: J. Fluids Engng 122, 2000.
Hewitt, G. F. 1978 Measurement of Two-Phase Flow Parameters. Academic.
Kawakita, C. & Takano, S. 2000 Microbubble skin friction reduction under the influence of pressure gradients and curved surfaces. J. Soc. Naval Arch. Japan 188, 1121.
Kawamura, T., Moriguchi, Y., Kato, H., Kakugawa, A. & Kodama, Y. 2003 Effect of bubble size on the microbubble drag reduction of a turbulent boundary layer. Proc. ASME Fluids Engng Conf. Summer Meeting 2003, pp. 1–8.
Kodama, Y., Kakugawa, A. & Takahashi, T. 1999 Preliminary experiments on microbubbles for drag reduction using a long flat plate ship. ONR Workshop on Gas Based Surface Ship Drag Reduction (Newport, USA), pp. 1–4.
Kodama, Y., Kakugawa, A., Takahashi, T. & Kawashima, H. 2000 Experimental study on microbubbles and their applicability to ships for skin friction reduction. Intl J. Heat Fluid Flow 21, 582588.
Kodama, Y., Kakugawa, A., Takahashi, T., Nagaya, S. & Sugiyama, K. 2002 Microbubbles: drag reduction mechanism and applicability to ships. 24th Symp. Naval Hydrodyn. pp. 1–19.
Kodama, Y., Hori, T., Kawashima, M. M. & Hinatsu, M. 2006 A full scale microbubble experiment using a cement carrier. Eur. Drag Reduction and Flow Control Meeting, Ischia, Italy, pp. 1–2.
Lapham, G. S., Dowling, D. R. & Schultz, W. W. 1999 In situ force-balance tensiometry. Exps. Fluids 27, 157166.
Lapham, G. S., Dowling, D. R. & Schultz, W. W. 2001 Linear and nonlinear gravity–capillary water waves with a soluble surfactant. Exps. Fluids 30, 448457.
Lu, J., Fernández, A. & Tryggvason, G. 2005 The effect of bubbles on the wall drag of a turbulent channel flow. Phys. Fluids 17, 095102.
Lumley, J. L. 1973 Drag reduction in turbulent flow by polymer additives. J Polymer Sci. Macromol. Rev. 7, 283290.
Lumley, J. L. 1977 Drag reduction in two phase and polymer flows. Phys. Fluids 20, S64S70.
McCormick, M. E. & Battacharyya, R. 1973 Drag reduction of a submersible hull by electrolysis. Naval Engrs J. 85, 1116.
Madavan, N. K., Deutsch, S. & Merkle, C. L. 1984 a Reduction of turbulent skin friction by microbubbles. Phys. Fluids 27, 356363.
Madavan, N. K., Deutsch, S. & Merkle, C. L. 1984 b Numerical investigation into the mechanisms of microbubble drag reduction. Trans. ASME I: J. Fluids Engng 107, 370377.
Madavan, N. K., Deutsch, S. & Merkle, C. L. 1985 Measurements of local skin friction in a microbubble modified turbulent boundary layer. J. Fluid Mech. 156, 237256.
Maxwell, J. 1881 A Treatise on Electricity and Magnetism. Clarendon.
Meng, J. C. S. & Uhlman, J. S. 1989 Microbubble formulation and splitting in a turbulent boundary layer for turbulence reduction. Advances in Fluid Dynamics, pp. 168217. Springer.
Meng, J. C. S. & Uhlman, J. S. 1998 Microbubble formation and splitting in a turbulent boundary layer for turbulence reduction. Proc. Intl Symp. Seawater Drag Reduction, pp. 341–355.
Merkle, C. & Deutsch, S. 1990 Drag reduction in liquid boundary layers by gas injection. Viscous Drag Reduction in Boundary Layers (ed. Bushnel, D. M. & Hefner, J. N.). Progress in Astronautics and Aeronautics AIAA 123, 351–412.
Merkle, C. & Deutsch, S. 1992 Microbubble drag reduction in liquid turbulent boundary layers. Appl. Mech. Rev. 45, 103127.
Nagamatsu, T., Kodama, T., Kakugawa, A., Takai, M., Murakami, K., Ishikawa, , Kamiirisa, H., Ogiwara, S., Yoshida, Y., Suzuki, T., Toda, Y., Kato, H., Ikemoto, A., Yamatani, S., Imo, S. & Yamashita, K. 2002 A full-scale experiment on microbubbles for skin friction reduction using SEIUN MARU. Part 2: The full-scale experiment. J. Soc. Naval Arch. Japan 192, 1528.
Nagaya, S., Kakugawa, A., Kodama, Y. & Hishida, K. 2001 PIV/LIF measurements on 2-D turbulent channel flow with microbubbles. 4th Intl Symp. on PIV, Goettingen, Germany.
Oweis, G. F., Winkel, E. S., Cutbirth, J. M., Perlin, M., Ceccio, S. L. & Dowling, D. R. 2008 Smooth-flat-plate turbulent boundary layer measurements at high Reynolds number. J. Fluid Mech. (submitted).
Pal, S., Deutsch, S. & Merkle, C. L. 1989 A comparison of shear stress fluctuation statistics between microbubble modified and polymer modified turbulent flow. Phys. Fluids A 1, 13601362.
Sanders, W. C. 2004 Bubble drag reduction in a flat plate boundary layer at high Reynolds numbers and large scales. Doctoral thesis, University of Michigan.
Sanders, W. C., Winkel, E. S., Dowling, D. R., Perlin, M. & Ceccio, S. L. 2006 Bubble friction drag reduction in a high-Reynolds-number flat-plate turbulent boundary layer. J. Fluid Mech. 552, 353380.
Schultz-Grunow, F. 1941 New frictional resistance law for smooth plates. NACA TM 17, 124
Shen, X., Perlin, M. & Ceccio, S. L. 2006 Influence of bubble size on micro-bubble drag reduction. Exps. Fluids 41, 415424.
Takahashi, T., Kakugawa, A., Nagaya, S., Yanagihara, T. & Kodama, Y. 2001 Mechanisms and scale effects of skin friction reduction by microbubbles. Proc. 2nd Symp. on the Smart Control of Turbulence, University of Tokyo, pp. 1–9.
Watanabe, O., Masuko, A. & Shirose, Y. 1998 Measurements of drag reduction by microbubbles using very long ship models. J. Soc. Naval Arch. Japan 183, 5363.
White, F. M. 1991 Viscous Fluid Flow. McGraw-Hill.
Winkel, E. S. 2007 High Reynolds number flat plate turbulent boundary layer measurements and skin friction drag reduction with gas or polymer injection. Doctoral thesis, University of Michigan.
Winkel, E. S., Ceccio, S. L., Dowling, D. R. & Perlin, M. 2004 Bubble size distributions produced by wall-injection of air into flowing freshwater, saltwater, and surfactant solutions. Exps. Fluids 37, 802810.
MathJax is a JavaScript display engine for mathematics. For more information see

Related content

Powered by UNSILO

Bubble-induced skin-friction drag reduction and the abrupt transition to air-layer drag reduction



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.