Justin Li

Arches' arches


Last week's question: what are the fluid dynamics of drafting?

Drafting is the practice of staying behind another moving object to reduce the energy needed to move. This is possible because when air moves past an object, there is a small area behind said object where the air cannot reform as rapidly, creating an area of low pressure. This low pressure is filled by pulling nearby particles, including those of the following object, towards it, hence saving energy on the following object's part.

Despite this somewhat technical explanation, I can't see to find fluid flow diagrams of drafting. Maybe someone would be so kind as to provide one?

This week's question: How are the stone arches in Arches National Park and elsewhere formed?