calcShipPwrProp.Rd
Calculates ship power (kW) using the propeller law.
calcShipPwrProp( shipSpeed, refSpeed, totalInstalledPwr, n = 3, serviceMargin, refSpeedType = "serviceSpeed" )
shipSpeed | Ship actual speed (m/s) (see |
---|---|
refSpeed | Reference speed of the ship (service speed or maximum speed) (m/s) |
totalInstalledPwr | Total installed main engine power (kW) (maximum continuous rated power) |
n | Exponential relationship applied to the ship speed ratio (dimensionless). Default = 3 |
serviceMargin | A service margin to account for weather and sea effects:
|
refSpeedType | Indicates if the reference speed is service speed or maximum speed:
|
power
Ship speed and actual draft are typically obtained from sources such as AIS messages or ship records.
serviceMargin = 10 or 15, based on IMO (Prpic Orsic and Faltinsen, 2012). 15 indicates 15% increased resistance in at-sea water conditions, and 10 indicates 10% increased resistance in coastal water conditions.
Note that service margin is treated as an added resistance here (instead of as a reduced efficiency) to maintain consistency with the other power models used in this library. (See MAN, 2011).
MAN Energy Solutions. 2011. "Basic Principles of Propulsion."
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