Friday, 28 October 2011

A new Dimension

This activity is also turning into a crash course in fluid dynamics!

All calculations for velocity and force are subject to Dimensionless transformations. Dimensionfull calculations of the quantities are carried out to determine the forces action on the ship. These forces are then made Dimensionless prior to adding all of the contributions together. The transformations use the following normalisation coefficients.

All velocities normalised by;

Factor = SRQT(g_dim*L_dim)

(seems to be linked to Froude number Fr)

All forces normalised by;

Factor = v_dim*rho_dim*g_dim

(seems to be linked to Reynolds number)


g_dim = gravitational constant
rho_dim = density
v_dim = velocity
L_dim = scaled length

Comment: Assumption is that these transformations are performed so that straight addition of the values can be carried out without the worrying about which units the calculations are performed in. It also allows the ship position and velocities to be converted easily between Nautical and SI units (e.g. Knotts to m/s) within the VB code.

No comments:

Post a Comment