DISPLACEMENT MECHANISM FORCES IN TUBE BUNDLE

M. Kokeisl, J. Linhart

Abstract

The article deals with experimental determination of fluid coupling forces acting on tubes that are in a cross flow. The real tube bundle is simulated by a System of cylindrical dummies. The method utilizes the possibility of superposition, and on this principle the forces are measured in pairs of dummies. During the tests both the tubes are excited by aerodynamic forces and also by sinus forces of two electrodynamic vibrators. There are 6 unknown values that must be solved: inertia, dumping, elastic aerodynamic and mechanical forces. The appropriate movement equation is complex, and so for filling its coefficients it is enough to measure three times: in flowing gas, in stagnant gas, and in not flowing liquid. During the measurements the deflection amplitude of dummies and frequency must be kept constant. The measured quantities are amplitude of deflections, vibrator current proportional to the force, and the phase between them. Only displacement mechanism forces are taken into account.

Keywords

mechatronical method, aerodynamic damping, aerodynamic stiffness

Download

IMEKO-WC-2000-TC3-P079.pdf

DOI

-

IMEKO TC

TC3 - Measurement of Force, Mass, Torque, and Gravity

Back to the proceedings