Numéro : 2728 - Year : 2018
Methodology for simulating the swim out of a torpedo from a submarine
Fabian PECOT, Thierry TAILLEFET - Sirehna – Nantes (France), Naval Group – Ruelle (France)
Among miscellaneous missions expected from a submarine, launching weapons from a tube is of major importance. To secure these launchings and to determine the safe operating envelope, the use of a numerical approach can constitute an interesting alternative to expensive trials.
This paper focuses on the development of a numerical methodology based on a CFD code and its overset grid approach allowing to simulate swim out torpedoes launching from a submarine tube. The code solves the strongly coupled URANS and weapon dynamics equations, with given propellers rotating velocities.
To validate this numerical methodology, full-scale trials of swim out launchings from a monodiameter tube immerged inside sea water at rest were carried out with a torpedo-like drone.
With the first CFD simulations performed with a monodiameter equivalent tube without guiding rails, a satisfying correlation was obtained between numerical and experimental results in terms of both weapon velocity and acceleration on one hand and pressures inside the tube on the other hand, except when the rear conical part of the drone is leaving the tube. Additional simulations demonstrated the necessity of modelling the guiding rails to accurately simulate the weapon hydrodynamic behaviour during this last step (despite of the increase of both the modelling complexity and the associated calculations durations).
This paper is written in English