Abstract
The WAHA computer code has been developed during the WAHALoads project in the frame of the 5th European Program. The main purpose of the WAHA code is to predict various mechanisms of single- and two-phase water hammer transients in piping systems. The WAHA code can simulate thermal-hydraulic transients with one-dimensional six-equation two-fluid model approximations and calculate the hydraulic forces on the piping system due to water hammers in two-phase flow. In the first part of the present paper, the main features of the WAHA code and its capabilities are presented : basic equations, specific closures laws, numerical scheme, possible boundary conditions, some basic results of water hammers induced by a rapid valve closure. In the second part of the paper, a description of the UMSICHT test facility PPP which has been used for water hammer tests inducing bubble condensation is given. The installation has been equipped with a new measurement technology including new wire mesh sensors with thermocouples for the measurement of condensation heat transfer and other innovative transient measurement techniques. From the UMSICHT data bank,some basic data have been chosen as reference case for validating the WAHA code. The third part deals with the simulation of several test cases using the WAHA code : Edwards pipe - Discharge of a hot liquid from a horizontal pipe. PPP water hammer tests – Depressurisation inducing cavitation water hammer initiated by a fast valve closure. Super Moby Dick experiment – Critical two-phase flow through a long nozzle. The results of these simulations are systematically compared with the experimental data, when available. It is concluded that the WAHA code has the abilitity to correctly predict various mechanisms of transients flows occurring in piping systems.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call