You need to determine the pressure drop-flow rate relationship for the pipe. If there is a valve, you need to determine the pressure drop-flow rate relationship for the valve. You then do a mass balance on the tank, and couple this with the ideal gas law and the pressure drop-flow rate relationships. This allows you to solve for the pressure in the tank as a function of time.sambyrd220390 said:I have a storage tank of 40 litres with compressed air, compressed to 9 bar (absolute), which is then fed through 8mm diameter pipe to a motor. The final pressure of the air is atmospheric (1 bar). The system is run until the storage container is depleted. Is there an equation that can find the time to take until the air runs out? Also i would like to plot this as a function of time, is there an equation to do this? I am assuming that temperature is constant.
In a closed system, pressure can either increase or decrease with time. This depends on the initial pressure, temperature, and volume of the system. If the temperature remains constant, the pressure and volume have an inverse relationship according to Boyle's Law. This means that as volume decreases, pressure increases and vice versa.
In an open system, pressure can change due to various factors such as changes in temperature, volume, or the amount of gas present. For example, an increase in temperature can cause an increase in pressure, while a decrease in volume can result in an increase in pressure. Additionally, adding or removing gas from the system can also affect the pressure over time.
When a gas is compressed, the volume decreases while the number of gas molecules remains the same. This results in an increase in pressure according to Boyle's Law. As the gas continues to be compressed, the pressure will continue to increase until it reaches equilibrium.
During a phase change, such as from a liquid to a gas, the pressure will remain constant. This is because the phase change occurs at a constant temperature, and according to the Ideal Gas Law, pressure is directly proportional to temperature.
In a vacuum, there is no pressure as there is no gas present. This is because pressure is defined as the force exerted by a gas on the walls of its container. Since there is no gas in a vacuum, there is no force or pressure exerted on the walls, and therefore, pressure does not change over time.