Stanford's ME 70 - Fluid Dynamics final project

Problem Statement

The project involves designing a space habitat called an O'Neill cylinder. The habitat is envisioned to resemble a long pill, designed to rotate in a manner that simulates Earth's gravity at its ends while allowing for zero-gravity conditions at its center. This is a realistic solution to many issues of space travel, with some private companies currently developing similar space stations to house humans in the next decade.

We will analyze a hypothetical O’Neill cylinder that closely resembles space stations currently being designed. It is 50m long and 3m in diameter. A water storage takes up 10 meters in length from one end of the cylinder and contains pure water, necessary for the astronauts. It will rotate about its center as shown in the diagram below. Standard atmospheric pressure air fills the rest of the space. To ensure the safety and functionality of the water storage section, two problems need to be addressed:

Emergency Water Ejection System: Due to the hazards of space debris, the cylinder must be able to quickly change its orbit if a collision is imminent. However, the weight of water makes the cylinder unable to accelerate fast enough to a new orbit. Therefore, a valve system must be designed to eject the water before beginning orbital maneuvers. Given a valve with an exit diameter of 0.35m and nozzle diameter of 0.5m, located axially on the cylinder end (see diagram), determine the time needed to fully discharge the stored water.

Nozzle Strength: The nozzle, which is bolted onto the cylinder, must withstand the water’s pressure when ejecting. Given an average ejection velocity of 10 m/s, determine the force on the valve and structure by the ejected water. Assume the nozzle has negligible thickness and length and the same dimensions as Part 1.