5. RESISTANCE
Michlet calculates a variety of resistance components. Wave resistance is
estimated using Michell's thin-ship theory augmented for (among others)
transom stern effects and boundary layer displacement thickness effects.
For monohulls and for the individual hulls of a multihull, output includes:
- Rh : Hydrostatic resistance on transom stern.
- Rf : Skin friction.
- Rwtrans : Wave resistance of transverse wave system.
- Rwdiv : Wave resistance of diverging wave system.
- Rw = Rwtrans + Rwdiv.
- Rform : Form drag.
- Rt : Total resistance.
- Rr : Residual resistance = Rt -
Rf.
Note that for supercritical depth-based Froude numbers, Rwtrans
is always equal to zero: there are no transverse waves!
As well as the components defined above, Michlet also calculates the
following interference resistance components:
- Rwtinter : Interference resistance of transverse waves.
- Rwdinter : Interference resistance of diverging waves.
- Rwinter = Rwtinter + Rwdinter.
Note that for these interference components, positive values mean
no beneficial interference, (i.e. resistance is increased) negative values
mean that there is some beneficial wave cancellation (i.e. resistance is
decreased).
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