Full-Scale Wake Measurements

KED Photonics offers velocity measurements at full-scale ships and maritime large scale structures. The data can be used for validation of numerical calculations and for optimization of cavitation prediction methods. The optical measurement techniques, adapted for marine use, are designed for large observation distances and high data rates.

Typical parameters for the detection of a full scale two-dimensional, three-component wake field (2D-3C)

Measuring distance:

– Up to 10 m below the ship’s hull, depending on the design of the optical access and the water quality

Measuring field:

– Up to approx. 5 m x 7 m

Time requirements:

– Approx. 2 min measuring time per measuring point

– Depending on the desired local and temporal resolution

– Installation and calibration times depend on the individual objective

Measurement accuracy:

– 1 % random error for mean velocity

– 3 cm maximum systematic error in spacial location

Requirements:

– Minimum two portholes as optical access in ship’s hull

Further parameters:

– Phase-resolved measurements to identify propeller influence and its higher harmonics

– Recording of ship movement (roll and pitch) via inclination and acceleration sensors