A note on flow-induced force measurement of oscillating cylinder by loadcell

The paper presents a systematic understanding of the importance of the quiescent-fluid added mass consideration in the estimation of loadcell-measured fluid force acting an oscillating cylinder. The output of the loadcell of a cylinder oscillating in quiescent fluid captures the cylinder inertia, added mass inertia, and fluid damping forces. When a cylinder-loadcell system undergoes flow-induced vibrations, the loadcell captures flow-induced fluid forces on the cylinder, the cylinder inertia, the quiescent-fluid added mass inertia, and the quiescent-fluid added damping force. To correctly estimate the flow-induced force on the oscillating cylinder, the cylinder inertia, quiescentfluid added mass inertia, and quiescent-fluid added damping forces have to be subtracted from the loadcell output. To approximate flow-induced force using a loadcell, quiescent-fluid added mass inertia and quiescent-fluid added damping forces have not been considered in the literature while the former has a great contribution to the loadcell output. If the quiescent-fluid added mass inertia is not considered, the phase relationship between the response and estimated force may not be consistent but defers depending on the quiescent-fluid added mass. The present systematic analysis of forces and added mass would be handy for postgraduate studies, researchers, and engineers.