The Use of Suction to Suppress Disturbances in Laminar Flow Caused by Insect and Other Surface Debris

Eustace, R; Barrett, R V
October 1999
Proceedings of the Institution of Mechanical Engineers -- Part G;1999, Vol. 213 Issue 5, p277
Academic Journal
Aircraft that employ extensive laminar flow for drag reduction need measures to counter the potential breakdown to turbulence caused by surface debris picked up near the ground. Decontamination methods are being developed but may not be suitable where suction through microperforated skins is used to control the flow, owing to the likelihood of hole blockage. This paper examines an alternative, where the existing suction system is used to draw away the developing turbulent wedges behind individual particles, thus providing a degree of tolerance to surface contamination. A wind tunnel investigation was conducted, using a flat plate model with a configurable suction region, to simulate the essential features of the boundary layer on a laminar flow engine nacelle. This enabled the influence of the various flow and geometric parameters to be assessed. The results, taken at Reynolds numbers/m in the range 1.5--4.5 × 10[sup 6], showed that turbulent wedges could be stabilized and removed, but that this required high levels of suction. The attendant increases in drag and suction system power make the method unattractive economically, although this situation would change if the increased suction could be applied only where required. The condition of self-induced transition at high suction flows was also investigated and was shown to limit the speed at which particle-induced turbulence could be suppressed.


Related Articles

  • Wonder egg. GARRISON, PETER // Flying;Dec98, Vol. 125 Issue 12, p106 

    Discusses aerodynamics, focusing on laminar and turbulent air flows on an airplane. Difference of turbulent with laminar flow; Discussion on airplane drag; Significance of aerodynamic resistance; Application of aerodynamics in designing a car.

  • Reduction of flow-induced forces on a circular cylinder using a detached splitter plate. Jong-Yeon Hwang; Kyung-Soo Yang; Seung-Han Sun // Physics of Fluids;Aug2003, Vol. 15 Issue 8, p2433 

    Control of flow-induced forces on a circular cylinder using a detached splitter plate is numerically studied for laminar flow. A splitter plate with the same length as the cylinder diameter is placed horizontally in the wake region. Suppressing the vortex shedding, the plate significantly...

  • An Analytical Approach for Calculation of Critical Weber Number of Droplet Breakup in Turbulent Gaseous Flows. Omidvar, Amir; Khaleghi, Hassan // Arabian Journal for Science & Engineering (Springer Science & Bu;Dec2012, Vol. 37 Issue 8, p2311 

    An analytical approach for prediction of the ambient turbulence effects on critical Weber number of droplet breakup is suggested and validated against available experimental data. Critical Weber number is an appropriate criterion for prediction of droplet breakup initiation in inertially...

  • Experimental Analysis of a Turbulent Boundary Layer Encountering a 2D Embedded Cavity Surface. Smith, Jonathon A.; Lang, Amy W.; Hidalgo, Pablo; Wheelus, J. Nicole; Mendelson, Leah // International Review of Aerospace Engineering;Aug2010, Vol. 3 Issue 4, p208 

    The characteristics of a turbulent boundary layer, initially formed over a flat plate, upon encountering a patterned surface consisting of two-dimensional embedded transverse cavities was experimentally studied using Digital Particle Image Velocimetry (DPIV). Results showed that the boundary...

  • The Research of the Flow of Bodies with Use of the Vector Form of the Newton's Law for the Viscous Liquid. Volobuev, Andrey N.; Petrov, Eugene S. // Engineering;Feb2011, Vol. 3 Issue 2, p162 

    On the basis of the vector formula of the Newton's law for a viscous liquid and the integrated vector form of the equation of an impulse for a viscous liquid for resistance and carrying power of a profile of any form and the big length dependences are found in a stream. Application of the found...

  • Sensitivity of aerodynamic forces in laminar and turbulent flow past a square cylinder. Meliga, Philippe; Boujo, Edouard; Pujals, Gregory; Gallaire, François // Physics of Fluids;2014, Vol. 26 Issue 10, p1 

    We use adjoint-based gradients to analyze the sensitivity of the drag force on a square cylinder. At Re = 40, the flow settles down to a steady state. The quantity of interest in the adjoint formulation is the steady asymptotic value of drag reached after the initial transient, whose sensitivity...

  • Optical Information About the Severity of Upcoming Contacts. Kim, Nam-Gyoon; Turvey, M. T.; Carello, Claudia // Journal of Experimental Psychology. Human Perception & Performan;Feb93, Vol. 19 Issue 1, p179 

    During locomotion the optical structure available to the eyes undergoes transformations. The well-known Reynolds number is the value of a dimensionless ratio constructed from the variables that enter into the law of inertia and the law of viscous flow. In situations of fluid flows, a critical...

  • Parametric study of unsteady laminar flows. Lipanov, A.; Karskanov, S. // Journal of Applied Mechanics & Technical Physics;Jan2010, Vol. 51 Issue 1, p4 

    Results of a parametric study of unsteady laminar flows are analyzed. Three-dimensional unsteady equations of hydromechanics for a compressible medium are solved. The range of the characteristic Reynolds number Re = 400–900 is considered. It is demonstrated that the laminar flow in a...

  • Homoclinic bifurcation in Blasius boundary-layer flow. Ehrenstein, Uwe; Koch, Werner // Physics of Fluids;Jun95, Vol. 7 Issue 6, p1282 

    Investigates a nonsemisimple resonance of phase-locked secondary instability modes in an attempt to elucidate the laminar/turbulent transition mechanism in a Blasius boundary layer flow. Description of the local nonlinear behavior; Formulation of the problem and linear results; Global...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics