Abstract: By visualizing the fluid object in question,the fluid flow status can be observed directly.According to the relative theory in fluid dynamics,it analyzes the following characteristic of solid tracer elements used to display the air current.The white powder of MgCO3 as tracer elements was directly put into the air stream,and the results of the experiment were compared with those of the theoretical analysis.The results show that it is an effective way to display the air current with powder of MgCO...

Key words: fluid experiment； solid tracer element； following characteristic； visualization；