The rhythm of your story (or the pacing) is built around your scene structure.
The length (or how long or short your scenes are) is what drives the flow.
Scenes with more exposition and description, for instance, will slow down the story. Dialogue will always speed a scene up.
A comedic scene will be shorter and more quickly paced than a dramatic scene, which tends to be longer and more drawn out.
But whether you're writing comedy or drama, the scenes should get shorter as you progress toward the climax. This is when the intensity of the story will be at its greatest, where the pages (hopefully) start turning themselves.
Otherwise, there should be a nice mix of points in your novel where the speed picks up, then pulls back a little--action vs. reaction--an incline that slowly builds to that key moment where everything unravels.
Be Brilliant!
~Katie~