[PDF] Top 20 Turbulent skin friction drag reduction control by spanwise motion

... flow control simulations, or the body force can be parametrised first, as done by Maden et ...the skin-friction drag reduction, and a series of parameter studies is going to be ... See full document

... of turbulent streaks is produced by introducing a Lorentz-type body force to the LNSE; a coarse-grained optimization over a small set of forcing parameters is then performed to find a near-optimal ...streak ... See full document

... minimum spanwise wall velocity Wmin is required for a drag reduction, with Wmin increasing as the period of oscillation decreases as the reduction in the penetration depth of the Stokes [r] ... See full document

... the turbulent enstrophy balance, Ricco et ...the turbulent enstrophy equation, which is balanced by the change in turbulent dissipation near the ...wall motion, they showed that the ... See full document

... a turbulent boun- dary-layer, ...and skin friction should be studied (this constitutes a biomimetic ...affects skin drag reduction has been studied by many researchers using ... See full document

... a skin friction reduction was observed, a secondary vortical flow was ...studies skin friction reduction had been achieved by manipulating the transverse velocity component ... See full document

... Controlling turbulent flow artificially was believed to be extremely difficult several decades ago, until the discovery of turbulent coherent structures and improved understanding of the underlying physics ... See full document

... the skin of fast swimming ...shark skin together with the addition of mucus within the ...physical drag reduction mechanism was provided analytically by Luchini et ...the spanwise ... See full document

... of turbulent boundary layers ...high skin-friction observed in turbulent boundary layers ...sweep motion owing to a strong streamwise vortex is believed to create a region of high ... See full document

... opposition control method has proved to be very useful for developing more practical control strategies which utilised only wall information ...suboptimal control, Lee et ...the control input, ... See full document

... passive control of turbulence transition being able to modulate the value of the critical Reynolds number for parallel wall bounded ...bounded turbulent flows have shown a potential for drag ... See full document

... The pipe system was the same used in [60, 55, 16] (see Fig. 1 in [60]). The mucilage is deposited in the storage tank and after 3 h of mixing the solution goes directly to a vessel. The vessel is connected to a ... See full document

... fluid drag needs to be added to the robot manipulator dynamics. The fluid drag on an object is proportional to the square of the object’s speed ...fluid drag always has a positive value in the ... See full document

... of turbulent channel numerical simulation flow was used as a testing ground for a simple distributed control scheme.In an spanwise highlow-speed the to attempt cancel and streaks, wall v[r] ... See full document

... of turbulent drag reducing ...polymeric drag reduction. Generally it is assumed that polymers in turbulent flow must be highly stretched before they can effectively change the turbulence ... See full document

... CFD analysis of an three arbitrary cross sectional pipe i.e. circular, triangular and rectangular pipe have been performed. While analysis the flow, all the three pipes have same cross sectional area so that the fully ... See full document

... rough-walled turbulent boundary layer with sand-grain roughness length-scale k s = αx that varies linearly with streamwise distance is first developed, with α a dimensionless ...local turbulent ... See full document

... spanwise flow, show that the growth of the LEV begins at the start of translation and continues until the vortex becomes unstable, detaches from the leading edge and is shed into the wake. Subsequently, a ... See full document

... 15% reduction in sized take-off weight, 20% improvement in L/D, 27% reduction in fuel usage, 27% lower thrust, and 12% lower operating empty weight when compared to a similar tailed ... See full document

... Abstract. Drag analysis is vital to measure the performance of the autonomous underwater vehicle (AUV) as well as the AUV ...previous drag studies is regarding to the shape and swimming method that ... See full document