Compactness Rate Research Articles

A Numerical Simulation of Sea Ice Cover in Hudson Bay

Abstract Hibler's dynamic-thermodynamic sea ice model with viscous-plastic rheology is used to simulate the seasonal cycle of sea ice motion, thickness, compactness, and growth rate in Hudson Bay under monthly climatological atmospheric forcing and a prescribed ocean surface current field. The sea ice motion over most of the domain is driven mainly by the wind stress. Wintertime sea ice velocities are only of the order of 1–5 (× 10−4 m s−1) due to the nearly solid ice cover and the closed boundary constraint of Hudson Bay. However, the velocities rise to 0.10–0.20 m s−1 during the melting and freezing seasons when there is partial ice cover. The simulated thickness distribution in mid–April, the time of heaviest ice cover, ranges from 1.3 m in James Bay to 1.7 m in the northern part of Hudson Bay, which compares favorably with observations. The area-averaged growth rate, computed from the model is 1.5–0.5 cm day−1 from December to March, is negative in May (indicative of melting) and reaches its minimum v...

An Experimental Study of Direct Condensation on a Fragmenting Circular Jet

Direct-contact heat exchangers have received increasing attention in recent years because of their simplicity of construction, compactness, and high heat transfer rate. The present experiments were undertaken to provide technical data for the design of jet-type direct-contact heat exchangers in the laminar flow range. Flow instability and the transition from a circular jet to droplets were observed and discussed. A comparison between the measured heat transfer rate and the heat transfer rate predicted by Jacobs and Nadig's (1987) analytical models for a laminar circular jet is also given in the present investigation. It is found that the measured heat transfer rate is slightly slower than that predicted by Jacobs and Nadig's analytical model for pure vapor; however, the experimental data agree well with the analytical solution the effects of the air content in steam are taken into account.