General description

IIHR acquired new forces and moments measurement equipment with the acquisition of the towing-tank maneuvering test flow-map measurement system in August 2004.  The loadcell and signal conditioning equipment is supplied by Izumi Measuring Co., Ltd.  The loadcell is a strain-gage type with three channels for surge, sway, and heave forces and three channels for roll, pitch, and yaw moments.  Each force and moment channel is conditioned with its own amplifier.  The loadcell is attached between the PMM carriage and the model through a single-point mount.  One successful test campaign has been completed with the Izumi loadcell to investigate the forces and moments on a scale ship model for static drift, pure sway, pure yaw, and yaw and drift tests for a range of towing speeds, drift angles, amplitudes, and frequencies.

System specifications

Designed and built:  2004

Installation:  July 2004

Tests:  3 forces and 3 moments

Loadcell:  FM6-AL50 strain-gage type

Amplifiers:  6 DA-18K type

Force range (Fx, Fy, Fz):  ±500 N, ±500 N, ±500 N

Moment range (Mx, My, Mz):  ±50 N-m, ±50 N-m, ±200 N-m

Software:  Mori Engineering PMM software

Company

Izumi Measuring Co., Ltd.

Tel:  03-3768-5301

FAX:  03-3766-6264

Sample images

Photo of the Izumi loadcell

Photo of the Izumi amplifiers; three are for Fx, Fy, Fz and three are for Mx, My, Mz

In this photo, the loadcell is visible above the strongback and pitch and heave balances

Sample data

The forces and moment data at left is taken for model 5512 at Fr = 0.28 in pure sway, pure yaw, and yaw and drift maneuvers.  The model is either fixed at its static water line, free to pitch and heave, or free to pitch, heave, and roll.

Non-dimensional surge force

Non-dimensional sway force

Non-dimensional yaw moment