Measuring Sloshing Impacts During Full Scale Tests

This paper describes the measuring equipment that is used in the first full scale tests on a real membrane containment system subjected to action of breaking waves representative of sloshing impacts in LNG tanks. The whole test set up for these test is discussed but the focus is on the measurement equipment that is used to capture the wave breaking process before and during the impact using the combination of high speed video cameras and a specially designed optical instrument called the iCAM. The iCAM is a matrix of 640 optical sensors capable to differentiate between solid water, aerated water and air. The impact of the wave on and the response of the containment system was measured using a data acquisition system which is a high speed, synchronous sampling, single shot type system. A total of 300 sensors including pressure gauges, strain gauges and load cells are measured. The paper will describe how the pressure sensors were specially selected and explain why they include a special silicone coated membrane with high stiffness. The dynamic calibration process of the pressure sensors is described and is carried out using a specially designed drop test device. Finally, the performance of the measuring equipment during the 110 tests is evaluated.