Balance can be balance by location of objects such as Windows on a house, balance by volume or sizes of objects, balance by color (like desired brightness in a room).

The results show that the stiffness is dependent not only on the pressure and volume at static balance, but also on the change rates of efficient area and volume.

Based on that, the numerical of product leakage and its method of solving are proposed, which include volume balance calculations, heat transfer models and transients fluid flow models.