The directional solidification process of SCN-3wt%Salol transparent alloy is investigated in the presence of the shear flow at the liquid-solid interface.It is found that the shear flow induces a stabilizing effect on...The directional solidification process of SCN-3wt%Salol transparent alloy is investigated in the presence of the shear flow at the liquid-solid interface.It is found that the shear flow induces a stabilizing effect on planar interface.At higher pulling rates,oscillation of the growth pattern together with fluctuation of the growth velocity takes place.With the increase of the pulling rate,the interface growth pattern transits from"planar-cellular"oscillation to"cellular-dendritic"oscillation,and the periodicity increases.The modification of the growth pattern is due to the effect of the shear flow on solute distribution,and the time and history dependent character of interface morphology evolution also plays an important role in the formation of the oscillating growth pattern.展开更多
Recent and constant demands for greater power densities and smaller sizes of electronic systems have stimulated the growth of new designs of different passive heat transfer methods such as heat pipes. Particularly, OH...Recent and constant demands for greater power densities and smaller sizes of electronic systems have stimulated the growth of new designs of different passive heat transfer methods such as heat pipes. Particularly, OHPs （Oscillating Heat Pipes） are relatively novel devices, capable of removing high heat rates over long and short distances with not much temperature drop. This study concentrates on the design, building and assembling a test rig in order to analyse the flow pattern ofdeionised water through a 5 turns flat plate oscillating heat pipe under different heat inputs, which was made in the school of engineering and materials science of the Queen Mary University of London by two energy M.Sc. students. The filling ratio of the water is 40%. Furthermore an experimental study on the OHP thermal performance is carried out in order to examine the effects of different surface wet conditions： super hydrophilic, hydrophilic and cleaned brass. It is demonstrated the formation of liquid slugs and vapour plugs of the water along the channels. The experimental results showed that the hydrophilic surface tends to be more energy efficient. The heat transfer performance of the super-hydrophilic and hydrophilic is higher than brass by 5-12% and 15-20% respectively.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.50331040 and 50702046)
文摘The directional solidification process of SCN-3wt%Salol transparent alloy is investigated in the presence of the shear flow at the liquid-solid interface.It is found that the shear flow induces a stabilizing effect on planar interface.At higher pulling rates,oscillation of the growth pattern together with fluctuation of the growth velocity takes place.With the increase of the pulling rate,the interface growth pattern transits from"planar-cellular"oscillation to"cellular-dendritic"oscillation,and the periodicity increases.The modification of the growth pattern is due to the effect of the shear flow on solute distribution,and the time and history dependent character of interface morphology evolution also plays an important role in the formation of the oscillating growth pattern.
文摘Recent and constant demands for greater power densities and smaller sizes of electronic systems have stimulated the growth of new designs of different passive heat transfer methods such as heat pipes. Particularly, OHPs （Oscillating Heat Pipes） are relatively novel devices, capable of removing high heat rates over long and short distances with not much temperature drop. This study concentrates on the design, building and assembling a test rig in order to analyse the flow pattern ofdeionised water through a 5 turns flat plate oscillating heat pipe under different heat inputs, which was made in the school of engineering and materials science of the Queen Mary University of London by two energy M.Sc. students. The filling ratio of the water is 40%. Furthermore an experimental study on the OHP thermal performance is carried out in order to examine the effects of different surface wet conditions： super hydrophilic, hydrophilic and cleaned brass. It is demonstrated the formation of liquid slugs and vapour plugs of the water along the channels. The experimental results showed that the hydrophilic surface tends to be more energy efficient. The heat transfer performance of the super-hydrophilic and hydrophilic is higher than brass by 5-12% and 15-20% respectively.
