JANUARY 2017 - MARCH 2018
The goal of this study is to investigate which level of CFD tools will be required to generate data with sufficient accuracy to drive the PPP to success.
Specifically, the study will compare the results for two types of CFD tools, panel code versus RANS. Using a simpler panel code will require many less man hours, and thereby be more cost efficient than a more demanding RANS code. Thus the study aims to provide guidelines for which data could be generated by a panel code, and which data necessitates the use of RANS. Or, in other words, we’ll provide guidelines for the most cost effective implementation of the PPP against a documented and understood trade-off in accuracy.
The two main components of a modern VPP, aero and hydro, are to a large extent based on CFD. Hence the study will cover both these VPP components.
The plan is to compare “Flow” (North’s aero panel code) versus “OpenFoam” (RANS) and "Star-CCM+" (RANS) over a sweep of apparent wind angles to quantify the limit to “Flow” for generating accurate and comparable data. We would use the same hull, representing a family of boats, used in the Wide Light test. This study will use an updated version of Flow, which now includes a new boundary layer and separation model that is expected to widen its applicable range. The study will also look into hull/mast/boom effect on the aero loadings to determine where these items should be accounted for, i.e. in the aero model, or in a separate module.
The study will run the panel code Das Boot with SYRF's Wide Light hull model to compare with the results from the mix of a panel code and multiple RANS codes documented in SYRF's report on this study last year. However, prior to running Das Boot with the Wide Light model, Das Boot author Michael Richelson (North Sails, Luna Rossa) will update the panel code with the intent of widening its applicable range.
SYRF is only paying for the services of North Design Group's JB Braun and Michael Richelson in the execution of PPP Phase 1. SYRF is not funding any of North Sails' technological developments.