Effect of Surface Friction On- the Structure of Barotropically Unstable Tropica
نویسنده
چکیده
The structure of barotropically unstable disturbances in the Tropics is studied with a two-level quasi-geostrophic model. An Ekman layer is attached to the lower boundary. The equations are linearized and the most unstable mode is found numerically by using the initial value technique. Computations are made for a shear-zone wind profile and a jet profile; these fields are independent of height. The disturbance structure is found to be critically dependent on the absolute vorticity gradient in the mean flow. The predicted disturbance structures contain a number of features that are observed in tropical wave disturbances.
منابع مشابه
Effect of heat treatment on the grain structure and mechanical properties of Al-7075 friction stir weld
The fine grain structure of friction-stir welded aluminum alloys is unstable during post weld heat treatment and some grains abnormally grown. In this study, the sequence of abnormal grain growth during T6 heat treatment of Al-7075 friction-stir weld and its effect on mechanical properties of the weld was studied. The results showed that heat treatment in 510 ˚C resulted in drastic grain growth...
متن کاملEffect of heat treatment on the grain structure and mechanical properties of Al-7075 friction stir weld
The fine grain structure of friction-stir welded aluminum alloys is unstable during post weld heat treatment and some grains abnormally grown. In this study, the sequence of abnormal grain growth during T6 heat treatment of Al-7075 friction-stir weld and its effect on mechanical properties of the weld was studied. The results showed that heat treatment in 510 ˚C resulted in drastic grain growth...
متن کاملEffect of surface roughness on steel-steel dry friction coefficient
The influence of surface roughness magnitude and direction on dry static friction coefficient between two similar steel samples has been studied through an experiment. A testing apparatus has been designed and fabricated to measure the friction coefficient for a few forms of surface asperity. According to the results of the experiments, dry friction coefficient is affected by both magnitude and...
متن کاملThe Effect of Simultaneous Incorporation of PTFE Nanoparticles and Carbon Nanotubes on the Tribological Behavior of Ni-P Coating
In some engineering fields, wear resistance and a low friction coefficient are required at the sametime. In this research, PTFE nanoparticles and carbon nanotubes were co-deposited within Ni-Pmatrix to obtain an Ni-P-PTFE-CNT hybrid coating for wear resistance and a low friction coefficient.The tribological properties of the deposits were evaluated by pin on disc tribometer. T...
متن کاملEffect of N2 partial pressure on the structural and mechanical properties of TaN films
TaN films with different N2 partial pressure were deposited on 304 stainless steel using the magnetron sputtering method. The effect of gas pressure on the mechanical property, morphology and phase structure of the films is investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), microhardness testing, friction coefficient measurements, and wear mechanism study. The XRD results c...
متن کامل