Calculate air resistance (Caa) (dimensionless) using the Kristensen method.

calcKristCaa(
  shipType,
  dwt,
  tankerBulkCarrierGCargoShipTypes = c("tanker", "general.cargo", "chemical.tanker",
    "liquified.gas.tanker", "oil.tanker", "other.tanker", "bulk.carrier"),
  containerShipTypes = c("container.ship")
)

Arguments

shipType

Ship type (vector of strings, see calcShipType). Must align with tankerBulkCarrierGCargoShipTypes and containerShipTypes groupings

dwt

Ship maximum deadweight tonnage (vector of numericals, tonnage)

tankerBulkCarrierGCargoShipTypes

Ship types specified in input shipTypes to be modeled as tankers, bulk carriers and general cargo vessels (vector of strings)

containerShipTypes

Ship types specified in input shipTypes to be modeled as container ships (vector of strings)

Value

Caa (vector of numericals, dimensionless)

Details

Models the effect of realistic hull roughness on resistance, which is not captured in the frictional and residual resistance coefficients from tank towing operations.

This method this requires ship types to be grouped. Use the tankerBulkCarrierGCargoShipTypes, containerShipTypes grouping parameters to provide these ship type groupings. Any ship types not included in these groupings will be considered as miscellaneous vessels.

NOTE: within the container ship section of this calculation, estimations are made of the ships TEU:

  • Feeder: TEU = ((dwt/15.19)^(1/0.9814))

  • Panamax: TEU = ((dwt/28.81)^(1/0.902))

  • PostPanamax: TEU = ((dwt/37)^(1/0.875))

These come from: H.O. Kristensen (2016), "Revision of statistical analysis and determination of regression formulas for main dimensions of container ships based on data from Clarkson". Kristensen's SHIP DESMO model also uses another dwt/teu relation for post-panamax container ships with breadth > 49m. This equation has no inverse to map dwt to TEU and thus all post panamaxs are assumed to have the same dwt/teu relation for all breadths, described above.

References

Kristensen, H. O. and Lutzen, M. 2013. "Prediction of Resistance and Propulsion Power of Ships."

Kristensen, H. O. 2016. "Revision of statistical analysis and determination of regression formulas for main dimensions of container ships based on data from Clarkson."

Kristensen, H. O. "Ship-Desmo-Tool." https://gitlab.gbar.dtu.dk/oceanwave3d/Ship-Desmo

See also

Examples

calcKristCaa(c("bulk.carrier","container.ship","other.tanker"),c(70000,191144,20000))
#> [1] 5e-05 9e-05 7e-05
calcKristCaa(c("bulk.carrier","container.ship","other.tanker"),c(70000,191144,20000), tankerBulkCarrierGCargoShipTypes=c("bulk.carrier","other.tanker"))
#> [1] 5e-05 9e-05 7e-05