Inquiry about Ice flow module

[ime00001]

Hi,

I am modelling a monopile foundation which is interacting with ice.

1. The ice flow manual shows a list of ice models to choose from. However, the glue-codes have only the file IceFloe_IEC_Crushing.dat which uses one ice model. Do we have other IceFloe files that use other ice models?

2. I tried to change the ice velocity in the IceFloe_IEC_Crushing.dat and .fst file. However, this change had no effect on the outcome response (reactions, moments ...). I wonder what I missed?

3. Looking at the results of one run, I expected the shear force to be approximately equal and opposite to the applied ice force. However, this was not the outcome I got (see below). Any idea why?

Thank you.

[jjonkman]

Dear @ime00001,

I'm not too familiar with the IceFloe module (and haven't used it personally myself, but have you reviewed the IceFloe Project Final Technical Report: https://openfast.readthedocs.io/en/main/_downloads/3759bf4ddfb4d771864e4e6c56c855f2/Ice_Load_Final_Report.pdf?

Regarding (3), can you clarify what SubDyn outputs you are plotting?

Best regards,

[ime00001]

Dear jjonkman,

Yes, I am aware of this report. Thank you.

The SubDyn outputs I am plotting are base reactions at seabed: ReactFXss[N], ReactFYss[N] and ReactFZss_[N].

Regards.

[jjonkman]

Dear @ime00001,

The base reactions at the seabed (SubDyn output ReactFXss, etc.) are often the opposite as one would expect because these reactions loads are the loads the foundation applies to the substructure. If you prefer to output the loads the substructure applies to the foundation, you can switch the sign of the output with a minus sign out front (i.e., output "-ReactFXss" instead of "ReactFXss").

Best regards,

[ime00001]

Dear jjonkman,

This is true. Thank you.

Regards.

[ime00001]

Dear jjonkman,

The IceFloe module offers different ice models:

But, I am not sure how to select an ice model in the IceFloe input file below:

! Test input parameters for IceFloe ! ! Model selection and general inputs ! timeStep 0.1 duration 100 randomSeed 123 rampTime 10.0 ! ! General ice property inputs ! iceThickness 0.6 iceVelocity 0.5 iceDirection 0.0 refIceStrength 2200000.0 ! ! Tower configuration inputs ! towerDiameter 6 numLegs 1 towerFrequency 0.28 ! legX1 4.5 legY1 4.5 shelterFactor_ks1 1.0 loadPhase1 0.0 ! legX2 -4.5 legY2 4.5 shelterFactor_ks2 1.0 loadPhase2 45.0 ! legX3 4.5 legY3 -4.5 shelterFactor_ks3 1.0 loadPhase3 135.0 ! legX4 -4.5 legY4 -4.5 shelterFactor_ks4 1.0 loadPhase4 290.0 ! singleLoad 0 legAutoFactor 0 multiLegFactor_kn 1 ! ! Inputs for lock-in crushing ! iceType 4 shapeFactor_k1 0.900000 contactFactor_k2 0.500000

I could find only this IceFloe input file in 5MW_Baseline.

[jjonkman]

Again, I'm not an expert in the IceFloe module, but a quick-look at the IceFloe report linked above makes it clear that the ice load model is selected via input parameter iceType.

Best regards