How do you make a fake working geyser for a science fair project?

I do not recommend a fake geyser for a science proyect. Fake geysers are not hard to build but they requires heatin water and preassure nozzles to be formed. For amusements parks this works great but in a science proyect in a room might not be safe. Here is why...
The artificial geyser device comprises a sealed container located preferably underground in a shallow recess and filled with water. The container is provided with a heater for heating water to the level of boiling and with a common discharge pipe, one end of which is located in the container and can be adjusted with regard to the level of water while the opposite end extends to the atmosphere in the form of an eruption pipe with a supersonic nozzle on the output end. The common discharge pipe passes over the open ends of the U-shaped pipe arrangement. The device has a group of valves that selectively may change the direction of the eruption flow for passing to the atmosphere only through the common discharge pipe, only through the U-shaped arrangement, or through both simultaneously.