A RANS modelling approach for predicting powering performance of ships in waves

In this paper, a modelling technique for simulating self-propelled ships in waves is presented. The flow is modelled using a RANS solver coupled with an actuator disk model for the propeller. The motion of the ship is taken into consideration in the definition of the actuator disk region as well as the advance ratio of the propeller. The RPM of the propeller is controlled using a PID-controller with constraints added on the maximum permissible RPM increase rate. Results are presented for a freely surging model in regular waves with different constraints put on the PID-controller. The described method shows promising results and allows for the studying of several factors relating to selfpropulsion. However, more validation data is needed to judge the accuracy of the mode

Green ship technologies and kite assisted propulsion

Shipping is the key to international trade. Our aim should be to make it more environmentallyfriendly. The proliferation of 'green' legislation and heightened environmental expectationsgenerally have created new market opportunities and seen the emergence of technologicalsolutions that attempt to enhance the green profile of the shipping industry. This presentationwill discuss the opportunities that exist in the area of alternative sources of power and thepotential energy savings by design solutions. Reference will be made to the currenttechnology measures available and define the alternative sources of power that may beuseful for ship design. The second part of the presentation will discuss the current greenshipping technology outlook. Those are divided into technologies that may affect our industryover the short to medium term or over the long term. As a case study a brief analysis of theresults from a theoretical study into kite-assisted propulsion will be discussed

Development of a kayak race prediction including environmental and athlete effects

The aim of this study is to produce a simulator for sprint kayak racing which would allow the prediction of race times based on the physiological capabilities and mass of a given athlete. The simulator has been verified using established empirical data for the prediction of environmental effects and has been shown to be accurate, however verification of the physiological model is difficult to do by using general race data. An investigation into the fatigue model which has been implemented shows that further investigation is required to calibrate the simulator and produce more accurate results over a variety of distances. However, the simulator does show quite how sensitive the selection of appropriate level of effort is to the final race time for the 1000m

The use of a cap-mounted tri-axial accelerometer for measurement of distance, lap times and stroke rates in swim training

This paper will report some of the findings from a trial which recorded accelerometer data from six elite level swimmers (three female and three male, varying primary event stroke and distance) over the course of a regular 15 week training block. Measurements from a headmounted accelerometer are used to determine when the athlete is swimming, marking of turning points (and therefore distance and lap-time measurements), and is processed by frequency analysis to determine stroke-rate. Comparison with video where available, and with training plans and literature where not, have proven this method to be accurate and reliable for determining these performance metrics. The primary objective of this project was to develop a low-cost, simple and highly usable system for use in swim coaching, feedback from elite coaches has indicated that development of this could be an extremely useful addition to their training regime

Mission Status for Earth Science Constellation MOWG Meeting @ Sioux Falls SD EOS Aura

This presentation provides mission operations status for the Earth Observing System (EOS) Aura satellite for the past six-months (December 2017 through May 2018). It only contains information that is of interest to the International Earth Science Constellation (ESC) Mission Operations Working Group (MOWG) member missions. It will be presented at the bi-annual MOWG Meeting at the USGS EROS Data Center in Sioux Falls, South Dakota on Wednesday, June 12, 2018. These meetings have been occurring twice a year since the MOWG was formed in 2003. The presentation has been reviewed and approved by Eric Moyer, ESMO Deputy Project Manager Technical

ASSESSMENT OF ERROR LEVELS ACROSS THE DOMAIN OF A THREE DIMENSIONAL UNDERWATER MOTION CAPTURE METHODOLOGY

Assessing human movement underwater presents many challenges, and it is therefore important to understand error across the whole capture domain to ensure accuracy in resulting kinematics. This study assessed the accuracy across the capture domain of a submerged motion capture methodology. Six Qualisys cameras created an underwater capture volume of 8x2x2m. Average error levels across the domain were acceptable in two uncertainty trials (1.23mm ± 8.23mm and 1.34mm ± 9.65mm), but error increased at the ends and top of the domain. By selecting an area of interest for assessment that excluded areas with lower accuracy, error was reduced to 0.53mm (± 1.45mm). This study highlights the need to investigate error levels across a motion capture domain, particularly when this is a large volume, to ensure results obtained from investigations are reliable

IMPACT OF KINEMATIC MODIFICATION IN THE UNDERWATER UNDULATORY SWIMMING PERFORMANCE OF A SWIMMER

This work is a case study observing the impact of various kinematics modifications in the simulated pressure forces and hydrodynamic work done by an athlete performing maximum effort Underwater Undulatory Swimming (UUS). The studied athlete was recorded using a Motion Capture methodology. Seven key joints were identified to represent the athlete’s motion and their position were fitted with a fourth order Fourier series. This kinematic data was then modified to reduce or amplify the upper-body and lower-body motion but also to have a linear wave propagation. The kinematics (10 in total) were inputted in an unsteady 2D Computational Fluid Dynamics (CFD) solver, Lily Pad. Results suggest directions for improvement in the execution of the athlete’s swimming style, whether it is for reducing the hydrodynamic work done or minimising resistive forces