...Puxuan Li; Matthew Campbell; Ning Zhang; Steve J. Eckels This study proposes a numerical model to collect and analyze relationships between flow structures and drag forces on a microfin enhanced surface. We utilized a large eddy simulation (LES) with a localized, dynamic kinetic energy, subgrid...

... and drag are compared with the results on the flat substrate. Enhanced drag and significantly enhanced lift are observed as the test particle is situated near the summit of the hill. Finally, the powder hill has been modeled as a monolithic cone or wedge. A realistic powder hill has nonzero porosity...

... shedding. Aerodynamics Compressible flows Drag Free shear layers Gas dynamics Supersonic flows Transonic flows Unsteady flows Wakes The authors would like to express their sincere gratitude to A. Narayanaswami, V. Biju, and A. Narayana for their unstinted support during the model...

... lock-in error as the difference between Triantafyllou's fish Strouhal number and the tangent of the vortex-shedding angle, an experiment is discussed for measuring the minimum drag of live fish. It has been shown that vortex shedding in oscillatory wakes affects the upstream angle of attack...

... and, in modern times, pneumatic blowing and synthetic jet actuators have been employed to prevent flow separation and increase base pressure at the rear of road vehicles [ 57 , 58 ]. This, in turn, leads to drag reduction and improved fuel efficiency in road cars and heavy trucks. Another highly effective active...

... analysis are also carried out for the pitching blade. The performance of the investigated turbulence models is evaluated at various critical points on the hysterias loop of lift and drag coefficients. The predictions of the investigated turbulence models are in good agreement at lower angle of attack, i.e...

... rotates from β  = 40 deg to 150 deg, the amount of fluid decelerated will increase with G . This may be the reason for higher lift forces as G is increased. Mean drag coefficient ( C D ¯ ) decreases with the increase in AR. It also decreases with the increase in α...

... configuration is actuated by means of a synthetic jet boundary condition. Overall, the effect of the actuation is beneficial. The actuation of the AFC decreases drag, stabilizes the flow, and reduces the size of the side recirculation bubble. σ k u = σ k ( f k 2 / f ε...

...Upender K. Kaul; Nhan T. Nguyen A Reynolds-averaged Navier–Stokes (RANS) computational study was conducted to investigate the effect of various variable camber continuous trailing edge flap (VCCTEF) configurations on the lift and drag of a NASA generic transport model (GTM) wing section. Out...

... width, ( 19.28 mm ≤ W ≤ 25.75 mm ), and angle of attack, ( 0 deg ≤ ψ ≤ 12.6 deg ). A total of six wheels and five tires were tested. Coefficient of drag area ( C d A ) and coefficient of side force area ( C s A ) versus angle of attack (ψ) were measured using a multi-axis force transducer. Wind tunnel...

...Xin Zhang; Xili Duan; Yuri Muzychka Flow drag reduction induced by chemical additives, more commonly called drag-reducing agents (DRAs), has been studied for many years, but few studies can manifest the mechanism of this phenomenon. In this paper, a new mathematical model is proposed to predict...

... Division of ASME for publication in the J OURNAL OF F LUIDS E NGINEERING . Manuscript received February 17, 2017; final manuscript received November 5, 2017; published online January 9, 2018. Assoc. Editor: Oleg Schilling. 17 02 2017 05 11 2017 Bubbly flows Drag Fluid transients...

...Michell Luiz Costalonga; Bruno Venturini Loureiro; Edson J. Soares We analyze the use of water solutions of Xanthan Gum (XG) for drag reduction (DR) in annular spaces. We provide a direct quantitative comparison between the DR in an annulus and that in straight tubes. We can fairly compare the data...

.... , Nudds , R. L. , and Thomas , A. L. R. , 2003 , “ Flying and Swimming Animals Cruise at a Strouhal Number Tuned for High Power Efficiency ,” Nature , 425 , pp. 707 – 710 . 10.1038/nature02000 2 asknature.org c = damping c = fin chord C Dj 1 = drag...

... online October 19, 2017. Assoc. Editor: Daniel Livescu. 12 04 2017 02 09 2017 Complex flows Drag Duct Rotating fluids Channel Pipe flows Ball valve, as a necessary component in the pipeline system, is commonly used to regulate flow rate and flow direction or control...

... Science Foundation of China (Grant Nos. 51276046 and 51421063). c = wing chord C D = drag coefficient C L = lift coefficient K p = potential lift coefficient K v = vortex lift coefficient Re = Reynolds number based on the chord wing, Re = U...

... correlation. A f = forward projected surface area of a single roughness element A s = windward wetted surface area of the element C = a constant in the velocity profile, Eq. (4) C D = form drag coefficient C f = 2 τ w / ρu 2 s , skin friction coefficient...

...Shiyang Hou; Jibin Hu; Zengxiong Peng The drag torque caused by the viscous shear in open multiplate wet clutches has been studied in most available literature whose focus is placed on low circumferential speed. However, the drag torque increases drastically in the high circumferential speed range...

...; final manuscript received May 2, 2017; published online July 19, 2017. Assoc. Editor: Feng Liu. 11 07 2016 02 05 2017 Aerodynamics Drag Lift Pressure coefficient traces showing the effect of the h / c  = 0.04 flap for Xf/ c  = 0.913 and 0.988 are displayed in Fig. 11...

... NGINEERING . Manuscript received February 6, 2017; final manuscript received April 27, 2017; published online July 18, 2017. Assoc. Editor: John Abraham. 06 02 2017 27 04 2017 Boundary layers Drag Gas dynamics Measurement techniques PIV Fluid mechanics Wall shear stress τ w...