Accurate prediction of tropical cyclone (TC) intensity is important but challenging. In this study, a physically based algebraic decay model for predicting TC weakening after landfall over China introduced, which assumes the rate proportional to square maximum near-surface wind speed. model, parameter including topographic effect by modifying surface drag coefficient with normalized terrain hei...

In the off-equatorial region of Jupiter’s and Saturn’s atmospheres, baroclinic eddies transport angular momentum out of retrograde and into prograde jets. In a statistically steady state, this angular momentum transfer by eddies must be balanced by dissipation, likely produced bymagnetohydrodynamic (MHD) drag in the planetary interior. This paper examines systematically how an idealized represe...

in according to the simplicity of the lattice boltzmann method’s(lbm) algorithm and its benefits, it has been used as a successful method in computational fluid dynamics in the last decades. in this paper, lbm was used to simulate the flow over a cylinder. to analyze the application of lbm in simulation curved surface, different methods to compute drag coefficient were used. these methods are: ...

The main topic of this article is wave propagation in disordered media. Of particular interest is the long wave regime where an arbitrary rapidly varying orography is modelled as a (stochastic) disordered medium. A brief description of mathematical theory and results is presented. The apparent diffusive behaviour, predicted in the theory for the wave-orography interaction, is confirmed through ...

A method is described for measuring the local drag coefficient on a long cylinder which exhibits vortex-induced vibration (VIV). Results are shown from a field experiment in which a long flexible pipe was instrumented with two-hundred and eighty fiber optic strain gauges. The measured local drag coefficients are compared to a commonly used drag coefficient prediction formula. The formula is sho...

Lines of energy are deposited ahead of supersonic and hypersonic vehicles in order to create a low-density channel, through which a vehicle can travel with dramatically reduced drag. Temperature and pressure are both also reduced on the front surfaces of the vehicle, while density and pressure are increased at the vehicle base. When applied off-center, this technique can be used to control the ...

The drag force associated with gravity waves generated by flow over the world’s mountain ranges tends to decelerate the large-scale atmospheric circulation, and must be parametrized in global weather prediction and climate models, since it is still not adequately resolved by those models. Such parametrizations have proved to be of crucial importance for improving the skill of weather forecasts....

Satellite drag-coefficient is a highly dynamic parameter that captures the physics of interactions between atmosphere and satellite surface. Physical models, known as Gas-Surface Interaction Models (GSIMs), can be used to compute time variations in orbit. But many input parameters such models are not accurately, consequently introduce uncertainties drag-coefficient. This work outlines framework...

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...

The adjoint-based sensitivity analyses well explored in hydrodynamic stability studies are extended to calculate the sensitivity of forces acting on an aerofoil with respect to wall transpiration. The magnitude of the sensitivity quantifies the controllability of the force, and the distribution of the sensitivity represents a most effective control when the control magnitude is small enough. Si...