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Pre-Analysis & Start-Up

Pre-Analysis

Root Radial Force

The radial force is the outward force that comes from a spinning mass. It is equal and opposite to the reaction force at the root of the blade that keeps the blade connected to the hub. It can also be thought of as the mass times the radial acceleration.

You might remember from your Dynamics course that radial acceleration is equal to, 

{latex}
$$a_r=\ddot{r}-r {\dot{\theta}}^2$$ .
{latex}

Here, 

{latex}
$$\ddot{r}$$
{latex}

The radial force is simply equal to,

{latex}
$$F_r = m a_r$$
{latex}

Substituting the radial acceleration and expressing angular velocity as 

{latex}
\omega
{latex}

{latex}
$$F_r = m r \omega^2$$
{latex}

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