ADDED MASS PREDICTION OF UNDERWATER VEHICLE DYNAMICS USING CFD METHOD

• Main Author: BAMBANG RISWANDI - Nim: 13613040 , BAGUS
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21374
• Institution: Institut Teknologi Bandung

One of unsteady flow behavior on the hydrodynamic characteristics of underwater vehicle is the presence of added mass. This phenomena occurs when the vehicle is accelerated to cruise condition or it experiences the deceleration. The time dependent interaction between the surface vehicle and surrounding flow generates local induced flow that affects great changes of hydrodynamic forces. This gives significant influence on the stability of the vehicle. The added mass constitutes the emergence of an additional force becoming important input parameter to model and control underwater vehicle dynamics. This thesis reports the research on the added mass coefficient of underwater vehicles obtained through the Computational Fluid Dynamics (CFD) simulation method using CFX software. Added mass coefficient is calculated by performing an unsteady simulation or known as transient simulation. Computational simulations are based on the solution of Reynolds Average Navier-Stokes (RANS) equations. The simulated vehicle moves forward and backward periodically according to the sinus function at various reduced frequencies (0.1 Hz,0.25 Hz, 0.35 Hz ), 2 m constant amplitude. The simulation was performed at cruising depth of 10 m below sea level, and cruise velocity of 1.54 m/s (Re = 9.000.000). The simulation results include velocity contour, force variation and acceleration to frequency, and added mass component value at various frequencies.