Performance analysis of an unmanned under water vehicle using CFD technique

Unmanned Underwater Vehicle (UUV) is vehicle that is controlled by human or automatically and operated underwater for executing different task. For effective maneuverability, the hydro dynamic performance of the UUV has to be evaluated or predicted before employed in the workspace. CFD software was used in this study. The model was designed in CAD software. As the UUV was symmetric about XY plane axis, so half of the UUV body was simulated. It is seen that negative lift is present for all velocity at zero angle of attack. This is a great finding of the study. This is due to conning tower which is located upon the top surface. As the angle of attack change from negative to more positive value, negative lift shifts more quickly to positive value for higher velocity. At higher velocity Lift coefficient does not change so much with velocity. Same amount to drag experience by the UUV for different diving angle. A lot of variation was found with velocity as expected, since drag is proportional to the square of velocity. CD is almost same for all diving angle for different velocity, except for lowest velocity 0.2m/s. Further investigation is needed for this large variation. From lift curve it is seen that for 0.2m/s and 0.4m/s velocity almost always creating negative lift for all diving angle. But for 0.6m/s lift was positive. A considerable difference captured in CL at 0.2m/s and 1m/s for zero diving angle. This is an important finding of the study. Other Cl are not much differing for different diving angle. Pitching moment does not vary with diving angle for constant velocity. But considerable change found in velocity difference as expected. Pitching moment coefficients does not change above 5° diving angle for different velocity. But at low diving angle up to 5° the change is considerable.Unmanned Underwater Vehicle (UUV) is vehicle that is controlled by human or automatically and operated underwater for executing different task. For effective maneuverability, the hydro dynamic performance of the UUV has to be evaluated or predicted before employed in the workspace. CFD software was used in this study. The model was designed in CAD software. As the UUV was symmetric about XY plane axis, so half of the UUV body was simulated. It is seen that negative lift is present for all velocity at zero angle of attack. This is a great finding of the study. This is due to conning tower which is located upon the top surface. As the angle of attack change from negative to more positive value, negative lift shifts more quickly to positive value for higher velocity. At higher velocity Lift coefficient does not change so much with velocity. Same amount to drag experience by the UUV for different diving angle. A lot of variation was found with velocity as expected, since drag is proportional to the square of ...