糖盐双扩散对流系统的研究

RESEARCH OF SUGAR AND SALT DOUBLE DIFFUSION CONVECTION SYSTEM

物质在水溶液中的输运有很多种形式,双扩散对流机制是溶液中物质输运的一种非常重要的形式.本文主要研究双扩散对流机制在糖-盐溶液体系中对指进现象出现的临界条件、指进生长模式、溶液密度的影响等.本文中使用红糖-盐溶液体系,并利用抽膜法进行实验,简单易行.研究发现,当扩散系数大的溶液在下层,扩散慢的溶液在上层,其密度比在某一固定范围内,则会出现指进现象,指进长度随时间呈线性关系,其密度差越大指进生长越缓慢.

There are many kinds of form of substance transport in the aqueous solution,the double-diffusion convection mechanism is a very important form of material transport in the solution.In this paper,we study the salt finger phenomenon,double convection diffusion mechanism in sugar-salt solution in critical condition,salt finger growth pattern,the influence of solution＇s density on the growth of salt finger,etc.This article we uses the brown sugar-salt solution system,and uses the method of pump membrane in the experiment which is simpler and easier.In this study,we found that when high diffusion coeffcient solution in the lower,while slow diffusion coeffcient solution in the upper layer.If the density of the lower and upper layer solution are in a fixed range,there will be a salt finger phenomenon which the length has a linear relation with time and the the bigger difference solution＇s density is the slower salt finger growth.