# Morison Equation - Value of $k$ not working

Need a hand with the Morison Equation with $$k$$ giving me a headache.

I'm following a video online trying to calculate the force on a structure I am designing for work. I try to follow videos using their numbers to ensure I get the formulae right in excel, but I can't seem to understand why my $$k$$ value, even though it's the same, gives me a massive number.

The lady in the video summarizes the equation in red. I broke down each part such that my excel function does not become too complicated.

Morisons Equation (after integration):

$$\rho C_M\frac{\pi D^2}{4}\frac{2\pi H}{T^2}\frac 1k 1-e^{-kd}\sin(kx-\sigma t)$$

Waveform number:

$$k=\frac{2\pi}{\lambda}=\frac{2\pi}{224.7}=0.279$$

Breaking down values as follows:

ITEM Result
$$\rho C_M$$ 2050
$$\frac{\pi D^2}{4}$$ 0.7853
$$\frac{2\pi H}{T^2}$$ 13.1594
$$\frac 1k$$ 35.76212
$$1-e^{-kd}$$ 0.027575

My result, ignoring the trig function, equals 20894.13, which is not her 62.2 value.

• There are brackets around $(1-e^{-k d})$, and also $k=0.028$ . With these corrections we have 62190.7N approximately 62.2kN as expected. – Alex Trounev Jun 15 at 11:32