calcAdmPwr.Rd
Calculates ship power (kW) using the admiralty formula.
calcAdmPwr( totalInstalledPwr, shipSpeed, refSpeed, actualDraft, maxDraft, serviceMargin = 15, n = 3, refSpeedType = "serviceSpeed" )
totalInstalledPwr | Total installed main engine power (vector of numericals, kW) (maximum continuous rated power) |
---|---|
shipSpeed | Ship actual speed (vector of numericals, m/s) (see
|
refSpeed | Reference speed of the ship (service speed or maximum speed) (vector of numericals, m/s) |
actualDraft | Actual draft (vector of numericals, m) |
maxDraft | Maximum summer load line draft (vector of numericals, m) |
serviceMargin | A service margin to account for weather and sea effects:
Can supply either a vector of numericals, a single number, or rely on the default. |
n | Exponential relationship applied to the ship speed ratio (dimensionless). Default = 3. This argument is not vectorized, so supply a single number or rely on the default |
refSpeedType | Indicates if the reference speed is service speed or maximum speed:
Can supply either a vector of strings, a single value, or rely on the default. |
power (vector of numericals, kW)
Ship speed and actual draft are typically obtained from sources such as AIS messages or ship records.
This implementation assumes the following default values:
n = 3 (IMO greenhouse gas study)
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).
International Maritime Organization. 2014. "Third IMO GHG study 2014 - Final report." London: International Maritime Organization.
MAN Energy Solutions. 2011. "Basic Principles of Propulsion."
#> [1] 0.0000 187.2600 187.2600 187.2600 187.2600 313.2486 541.2936 #> [8] 859.5542 1283.0663 1826.8659 2505.9889 3335.4712 4330.3488 5505.6576