STA offers a wide range of hydrodynamic analysis services. We use commercially available software, including AQWA, WAMIT, and MDL Hydro, as well as our own STA BARMOT for calculating moton responses of large vessels in waves. We use OrcaFlex for simulations in the time domain.
Dynamic mooring analysis is generally performed with OrcaFlex, as illustrated in the video below.
Hydrodynamic analysis of fixed and floating structures, including harbors and breakwaters, often involves developing proprietary solutions. Wave energy converters are one example where special use of the available feature in Orcaflex enable the mechanical power generating mechanisms to be simulated.
The hydrodynamic analysis of tankers at single point moorings (SPMs) is done primarily with OrcaFlex and need much experience to get good reliable solutions, especially for rapidly changing wind conditions, caused by squalls, or sudden wind shifts.
In-house software, STA BARMOT, is used to calculate frequency domain motion response of barges and ships with large block coefficients in waves. STA BARMOT is a 6-degree-of-freedom rigid body motion caclulation, for floating vessels. The program provides virtually instant results using a minimum data set of vessel:
- Block Coefficient
For each degree of freedom, the hydrodynamic diffraction and Froude-Krilov forces are discretely calculated for wave attack in the primary plane of motion, at a range of wave periods. Mechanical admittance is calculated and dynamic response is computed. Response at intermediate attack angles is interpolated.
As well as producing displacement RAOs (Response Amplitude Operators) and wave drift forces (QTFs) for direct input to OrcaFlex, STA BARMOT produces a compact summary of vessel motions in any given swell condition, at zero Froude number (zero forward speed) as shown below.