The Research On Centrifugal Shear Flow Field And Its Application

The secondary flow is a familiar phenomena in the hydrodynamics . The theory of secondary flow has used in lots of high tech fields, such as aviation, bioengineering, water-treatment, preventing or controlling flood ,environment protecting , film separating and so on , which makes great success. So, we use the way of experiment and theory to study the secondary flow. The research work has been accomplished with the following achievements :(1)We build the testing model of centrifugal secondary flow field whose diameter is 300mm. By means of the Laser Dopper Velocimeter (LDV, SCD-21) measure and analyze the velocity distributing in the model . with the analyse of experiment data , we find that there are four circulation secondary flow field .( 2 ) Analyzing and validating the familiar secondary flow coefficient, such as Dean vortex, Taylor vortex and G?rtler vortex, we summarize the secondary flow coefficient . Then, we define a new variable h f in the Bernoulli equation . Based on it, we will get the coefficient of centrifugal shear ( L) and the coefficient of secondary flow (Z ) .(3)Making the centrifugal shear secondary flow theory appliance in coagufloccule and comparing the result of general flow field,the experiment data indicate that floccule agglomerate quickly whose amount is large ,and the sedimentation is rapid , floccule particles are tight. In a word ,the result is as 5～10 times as the general cogufloccuation .(4)Using the Froude rule and Reynolds rule in similitude magnifying theory, we magnify the model of centrifugal shear secondary flow field .Through coagu-flocculation indoors experiments and corresponding resemble magnifying experiments, the result indicate that it approach to indoors experiment .