The efficiency of helical strakes for the suppression of vortex excited oscillation and its application of steel stack in use

Abstract

To find out the best configuration of the strakes to suppress the vibration of stackswind tunnel experiments were performed. Based on the results of the test, the helical strakes were fitted to an actual stack.
The measurement of the vibration of the stack were carried out before and after the installations of the strakes and the designed helical strakes were proved to be successful.
In the design of the stack with appropriate helical strakes the vortex excited oscillation need not be taken into account. As a result, the structure of the stack can be expected to be more rational than plain stack without strakes.