Sailing Dynamics

NAISS 2024/5-243


NAISS Medium Compute

Principal Investigator:

Lars Larsson


Chalmers tekniska högskola

Start Date:


End Date:


Primary Classification:

20303: Vehicle Engineering

Secondary Classification:

20306: Fluid Mechanics and Acoustics



Chalmers is a National Sports University and is engaged in research within Sports and Technology. Until recently, sailing has been the largest area, but due to lack of qualified supervisors after my retirement (see below) it is no longer a focus area. A presentation of the work carried out up until a year ago may be found on the link: The presentation introduces a large number of projects, and the work has resulted in 34 external publications, 2 Licentiate theses, 14 MSc theses, 4 BSc theses and 6 project reports. Almost all work within the center has been numerical, so large computer resources have been required. The work carried out during the past year is presented in the Activity report, where it appears that the only remaining sailing project is Adam Persson’s PhD project, which is the most fundamental one of the sailing projects in the Centre. He develops a numerical technique for sailing yacht performance prediction in waves based on Computational Fluid Dynamics, strongly coupled to 6DOF rigid body dynamics (CFD-VPP). This calls for massive computer resources. As explained in the Activity report, there is a very large interest in sail-assisted ships at present. Considerable fuel savings (and emission reductions) are possible, and many projects are underway worldwide. Now, Adam’s CFD-VPP technique may be readily expanded to this area, and this development will be done after the completed PhD exam. However, already now a development of the aerodynamic model is underway in the PhD project by Karolina Malmek. Since sail-assisted ships will have many sails in one or two rows along the ship, sail-sail interaction will be important. In her Licentiate project Karolina has developed a sail model for this purpose, assuming undisturbed inflow (see the Activity report). During the coming year she will modify the technique to consider the velocity disturbance from the hull and the vertical velocity gradient due to the atmospheric boundary layer. Computational resources are thus required for both Adam and Karolina. For Adam large resources will be required to carry out the final computations for his PhD project: a performance prediction for a sailing yacht in waves including the dynamic sail model. Note that these resources were included in last year’s proposal, but were never used, since the development of a dynamic sail model took longer than anticipated (see the Activity report). These massive resources will however be needed only for a short period of time, say two months. Unfortunately, the exact time when the resources are needed cannot be fixed at present, since Adam is on leave for reasons out of his control (sickness in the family). Karolina will need considerably less resources, as her CFD computations will be for a simpler steady state problem without rigid body motions. This will be to validate her improved sail-sail interaction model including the hull and atmospheric boundary layer influence.