Session: FSI-02-02 Tube Arrays - 2

Paper Number: 106888

106888 - Generalization of Rotated Triangular Array Force Measurements in Two-Phase Cross-Flow 

The time-averaged quasi-static force measurement has shown a significance in studying the fluidelastic instability of tube arrays. Furthermore, measuring the fluid force phase from the unsteady force measurements could be used to directly investigate the dynamic behaviour of an array and predict the array fluidelastic instability onset. Force measurements were previously performed for a rotated triangular array with a pitch ratio of P/D=1.5. In this paper, a more compact spaced rotated triangular array is studied following the same measurement approach. This rotated triangular array has a P/D=1.33. Determining the relationship between the fluid force coefficients used in the quasi-steady model, and fluid force phase used to predict the fluid damping, is one of the main objectives of this work. This is in order to relate the fluid forces to the array pitch spacing. This should be a step toward generalizing the quasi-steady model for the rotated triangular array for various pitch ratios. In this paper, the quasi-static fluid forces, as well as, the unsteady fluid forces, are measured in single phase (water) and two-phase (air-water) cross flow. The quasi-steady model is solved to predict the fluidelastic instability onset of the array. Model results are also directly compared with vibration experimental results.

Presenting Author: Njuki Mureithi Ecole Polytechnique Montreal

Presenting Author Biography: Professor Njuki Mureithi is a full prefessor at Polytechnique Montreal, Mechanical Engineering Department.

Authors:

Sameh Darwish Ecole Polytechnique Montreal
Njuki Mureithi Ecole Polytechnique Montreal
Minki Cho Doosan Enerbility