False diffusion

Imagine you have a toy car and you want to make it move from your hand to your friend's hand. However, you can't just throw it because it might break or get lost. So, you decide to play a game where you move the car from one hand to the other by passing it through a tunnel made of your arms.

Now, think about a similar situation in which we have to simulate the motion of air or gases in a computer model instead of a toy car. We use mathematical equations to describe how air or gases move in real life. However, these equations are not perfect and can't always match the behavior of air or gases in reality.

One problem that can occur in these equations is called "false diffusion." It's like when you pass the toy car through the tunnel and it loses some of its speed and direction because of the friction between your arms. Similarly, false diffusion happens when the equations used to simulate the motion of air or gases introduce some unwanted changes in the speed and direction of these substances that are not actually happening in real life.

This can cause errors and inaccuracies in the simulation, and make the results of the model different from what is observed in reality. Scientists and engineers have to find ways to minimize or eliminate false diffusion to make their simulations more accurate and reliable.