Loads due to vortex induced vibrations (VIV) This load model is currently under development. 1. Description The VIV load model calculates vortex-induced vibration loads during dynamic analysis. It is used when VIV response due to current loading needs to be accounted for directly in the time domain simulation. The following VIV load options are available: Cross-flow loads only Cross-flow VIV loads are calculated based on the instantaneous relative flow velocity and vortex shedding frequency. This is the standard supported option. Cross-flow loads and in-line loads calculated separately Cross-flow and in-line VIV loads are calculated independently. In-line VIV loads only In-line VIV loads only. The VIV load coefficients (force coefficient, natural shedding frequency, frequency range) are non-dimensional and specified as part of the cross section properties. 2. Theory For details, see Theory Manual - Loads due to Vortex-Induced Vibrations for the load formulation and synchronization model.