In this video, a pyrotechnician breaks down the basics of his craft. At one point, he mentions a formula used in his industry: a shell will approximately 70 feet into the air for every inch of diameter it is. So for example, a one-inch mortar (a rather large consumer model) will launch about 70 feet into the air. A two-inch mortar, 140 feet into the air, and so on.
How does this correlate to the length of the launch tube needed? Or does it not matter at all (beyond the first few inches).
Also, do any fireworks rely on rockets for propulsion into the air? Or is all of their lift provided by the initial blast of the lift charge?
Skyrockets, essentially solid fuel rockets propelling a piece of fireworks, exist. Where I grew up, this was a popular thing for teenagers to do for New Year’s Eve. They are attached to a wooden stick that you put in an empty glass bottle, then you light the fuse and step back.
Bottle rockets are little things. There are larger rockets on sticks, and also rockets with classic cylindrical bodies and fins. In addition there are a number of different types of helicopters like this classic Silver Jet.
Yup. The fireworks use black powder for their solid fuel; traditional model rocket motors use the same thing.
That said, model rocketry now has several different “classes” of rockets, based on motor power. Most black-powder motors are considered “low-power” these days; most “mid-power” and all “high-power” motors use a composite propellant (aluminum perchlorate, aluminum powder, and a binding agent).