YDE-Fix: design, simulation and testing of a 1:3 scaled model of a remotelY towed operateD vehiclE for coastal area research of marine traffic emissions

Black Carbon (BC) is part of soot and one of the primary ship emissions. Several studies have shown that BC has an impact on global warming and that it is harmful to health so there is the necessity for regional and global regulations of BC. To investigate ship emissions and pollution in the atmosphere and in waters, sensors and measurement platforms are being developed in the MarTERA ERA-NET Cofund funded project MATE (MAritime Traffic Emissions: A monitoring network). One of these measurement platforms is a remotelY towed operateD vehicle (YDE-Fix) for coastal and open sea areas. YDE-Fix is equipped with oceanographic sensors to measure the main in-situ parameters like temperature, turbidity and oxygen as well as dBC, dissolved Black Carbon. A special feature in the design is a flow through tube were sensors which react sensitive to ambient light can be attached. The shape of YDE-Fix is designed by using the Myring-hull-profile equations and engineered as small as possible to create low drag forces in the water. YDE-Fix is equipped with eight fins, four stern fins which can be remotely controlled. Thus it is possible that the towing vehicle can ascend and descend and an undulating movement is possible to measure in different water depths up to 20 m. In addition, the four central fins have a fixed pre-set inclination. The two horizontal central fins generate always a downward force against the towing rope. Another benefit of YDE-Fix is the rotating bearing-mounted slip ring for the towing cable to prevent an additional rolling during operation due to the towing force. To ensure that the hull shape and design of the towed body behaves as planned, a prototype has been built at a scale of 1:3. The scaled model was also simulated with CFD (Computational Fluid Dynamics, simulation program) to get a better prediction of its drag and lift forces at dynamic inflow velocities. The scaled model was successfully tested in a towing tank to validate the simulation results as well as the drag estimations by ITTC'57. The evaluation shows that the results of the CFD simulation agree well with the measured drag forces of the towing tank tests. This confirmed and thus validated the CFD simulation results in the towing tank in a reproducible manner.