QSHIP HYDRODYNAMIC SUITE
QSHIP offers a hydrodynamic suite for seakeeping calculations and workability. The hydrodynamic suite contains (depending on the selected version) two potential flow methods; the strip theory code SHIPMO and the panel code PRECAL_R. QSHIP calculates ship motions, velocities, accelerations and relative wave elevation of a ship in waves. Based on this, QSHIP can calculate the uptime based on exceedance of defined criteria like illness rating or local accelerations.
INTEGRATED APPROACHThe workflow of QSHIP provides guidance and easy use of the complete chains of pre-processing, calculations and post-processing.
ConvertHullFormCalculations start with a description of the ships hull, either by panels or sections. The included Rhino-plugins and ConvertHullForm tools convert a wide range of file formats into the appropriate QSHIP format.
SHIPMOSHIPMO is the MARIN implementation of strip theory. It is the fastest way to obtain a first reliable impression of the ship motions. SHIPMO gives an answer in a few minutes, depending on the number of headings, speeds, frequencies and sections.
SHIPMO provides the transfer function in all 6 degrees of motions and has different methods to include the viscous roll damping (e.g. IKEDA, FDS, Nobel Denton, user defined). It can include damping contributions from appendages like fins, rudders, skegs and anti-roll tanks. Because of the strip theory assumptions, SHIPMO is limited to slender ship types.
PRECAL_RThe PRECAL_R code is being developed by the MARIN Cooperative Research Ships (CRS) and includes an implementation of 3-dimensional potential theory. Since panel codes use a more detailed description of the hull, the diffracted and radiated waves can be accounted for in all directions. Therefore, PRECAL_R is not limited to the slender ships only, but can also be used for more full ships. Detailed calculations provide improved results of the relative wave height and added resistance in waves. All options on roll damping and appendages are taken care of by the user interface and are equal to those available in SHIMPO. Calculation times are reduced by taking advantage of all computer cores. Nevertheless, the more detailed methods of panel codes will take several hours to compute, depending on the number of panels, headings, speeds and wave frequencies.
Uptime/downtime analysisIn the MARIN OpCal code of QSHIP the significant numbers for a range of signals can be calculated for any sea state. In the operability viewer, these are combined with actual wave statistics to evaluate the time that a criterion is exceeded in that specific location. This includes the calculation of comfort indicators such as MII, MSI and local accelerations but also relative wave elevation. When SHIPMO is used, these relative wave elevations are based on the undisturbed waves, using PRECAL_R the radiated and diffracted wave components are included as well.