Numerical diffusion

Alright little one, numerical diffusion is like when you're drawing a picture on a piece of paper and you use a crayon to color it in. But sometimes, when you color too hard or too much in one spot, the color can spread out and make the picture look blurry or smudged.

In a similar way, when we use computers to simulate things like air flow or ocean currents, sometimes the calculations can cause the numbers to spread out and make the simulation less accurate. This can happen especially for areas where the flows change rapidly, like around corners or in windy conditions.

So just like you need to be careful when coloring with a crayon, scientists and engineers need to be careful when doing these simulations and work to minimize this numerical diffusion. This means using more precise calculations and making sure the computer program is designed to handle rapid changes in flow. With practice and care, we can get an accurate picture of the world around us using these simulations.