Development of a new type of active vertical sand trap

A new active vertical sand trap is designed to implement the performance that airflows in all sampling tubes at different height are allowed simultaneously approach to the isokinetic state. The comparative experiments of the new active sand trap with a traditional passive one are carried out in a wind tunnel, where a new non-dimensional parameter is introduced to evaluate the stagnant effect on airflow of the trap. The results indicate that the new sand trap is able to remarkably reduce the stagnant effect with fine adaptability under different wind conditions, and the vertical mass flux measurements verify the higher efficiency of the new trap, especially in high speed wind and near bed region.