I am researching flow through blister packs and trying to derive an equation that can relate flow rate to a plunger position. If I cannot describe the problem well, I will upload a picture that can give a better idea. I have an igloo shaped blister pack made of aluminum foil. A plunger moves downward into the dome shape of the igloo. The blister pack is filled with liquid which is released once a seal at the center of the igloo entrance is broken. The increase in pressure inside the deformed blister pack causes the break in the seal. I want to find out the flow just at the instant the seal breaks as well as how the flow rate changes as time passes/plunger moves inwards. Some of the challenges I am facing are - The plunger impresses into the dome for a finite distance until the seal is finally broken. Since the liquid (water) is incompressible, it implies that the foil expands slightly to accommodate this loss of volume. The expansion of the foil has it's own elasticity and will store pressure/energy until the seal is broken. This stored energy will contribute to the pressure from the plunger when the seal breaks. There is a very high possibility that I may be complicated things for no good reason. Please tell me if I could model it simpler. In summary, I want to find the flow rate against the position of the plunger into the dome. Any help towards approaching the problem will be highly appreciated. Thank You !