FYKOS Year 26 Series 3 Problem 5 — Gas crises · FYKOS 26 #26.3.5
Physics · mechanics · thermodynamics
Problem
A Siberian gas pipeline with a liquefied natural gas needs to be closed. Váňa Vasilijevič decided to do this manually by closing a frictionless valve. What is the work he needed to do so? What is the force he acted on the valve with (choose an appropriate parameter to describe it)? You can imagine the valve as a board that is being inserted into the pipeline (the pipeline is perpendicular to this board). Initially, the pressure inside the pipeline was p=2MPa. Its cross-section is square-shaped with a side of length a=1m. The board is d=10cm wide, the density of liquefied natural gas is ρ=480kg⁄m, and its flow rate is q=20m3s.