Wind tunnel measurements of the effects on twodimensional section characteristics of square ridge excrescences and of some gaps typical of those found round trailing-edge controls have been made at high subsonic Mach number and at Reynolds numbers up to 15.6 x 106, based on section chord length. The incremental drag due to a square ridge was found to be generally underestimated by applying an e...

A lock exchange experiment is used to investigate the propagation of gravity currents through a random array of rigid, emergent cylinders which represents a canopy of aquatic plants. As canopy drag increases, the propagating front varies from the classic profile of an unobstructed gravity current to a triangular profile. Unlike the unobstructed lock exchange, the gravity current in the canopy d...

The nonlinearity of the Navier-Stokes equations makes predicting the flow of fluid around rapidly moving small bodies highly resistant to all approaches save careful experiments or brute force computation. Here, we show how a linearization of the Navier-Stokes equations captures the drag-determining features of the flow and allows simplified or analytical computation of the drag on bodies up to...

This paper studies several problems that may exist in the aerodynamic design of low Mach number general aircraft, and discusses characteristics pressure distribution some related airfoils while part is verified by a multi-point laminar airfoil case. Firstly, issues which such as relatively large zero-lift drag coefficient, high stall performance requirements, variation range Reynolds number, ar...

Motivated by an important discovery on the drag scaling law (the 4/3 power law) of a flexible fibre in a flowing soap film by Alben et al. (Nature vol. 420, 2002, p. 479) at high Reynolds numbers (2000<Re< 40 000), we investigate drag scaling laws at moderate Re for a compliant fibre tethered at the midpoint and submerged in an incompressible viscous flow using the immersed boundary (IB) method...

The authors introduce a three-parameter characterization of the wind speed dependence of the drag coefficient and apply a Bayesian formalism to infer values for these parameters from airborne expendable bathythermograph (AXBT) temperature data obtained during Typhoon Fanapi. One parameter is a multiplicative factor that amplifies or attenuates the drag coefficient for all wind speeds, the secon...

Cross-corrugated triangular channels increase heat transfer in heat exchangers. The mixing effect increases the heat transfer coefficient at the surfaces. In this study, the fluid flow and heat transfer in a triangular corrugated channel are modeled under two constant heat fluxes and different Reynolds numbers. In order to validate, k-ω turbulence model is used. Also, the effect of magnetic fie...

This paper presents 2-D finite volume method for computation of viscous drag based on Reynolds-averaged Navier-Stokes (RANS) equations. Computations are performed on bare submarine hull DREA and six axisymmetric bodies of revolution with a number of length-diameter (L/D) ratios ranging from 4 to 10. Both structured and unstructured grids are used to discretize the domain around the bodies. Diff...

In order to obtain the damping and resistance coefficients of a pendulum, we constructed an optical system containing photogate for measuring speed pendulum at lowest point motion. The consisted photoresistor, laser, mechanical body, ball. A 3D printer was used produce body balls various sizes. Furthermore, Arduino automate measurement motion increase precision. We found that coefficient propor...

Inverse models are developed that use data and dynamics to estimate optimally the breaking-wave-driven setup and alongshore current, as well as the cross-shore forcing, alongshore forcing, and drag coefficient. The inverse models accurately reproduce these quantities in a synthetic barred-beach example. The method is applied to one case example each from the Duck94 and SandyDuck field experimen...