INVESTIGATION OF HYDRODYNAMIC FORCES FOR AUV BARE-HULLS BY USING SEMI-EMPIRICAL EQUATION AND CFD

This paper addresses the problem of autonomous underwater vehicle (AUV) modeling and parameter estimation as a means to predict the dynamic performance of underwater vehicles and thus provide solid guidelines during their design phase. The use of semi-empirical methods to estimate the hydrodynamic coefficients of a popular class of AUVs is discussed. A comparison is done with the results obtained by using a semi-empirical equation at different angles of attack with results obtained by using CFD and experimental results. Finally,it is in our interest to investigate the range of angle of attacks for which semi-empirical equations are valid. The semi-empirical method was originally developed to predict the aerodynamic coefficient onairships butwas later refined for underwater vehicles like submarine and AUVs. This paper describes different types of semi-empirical equations and provides comparative results obtained from these equations. This paper also indicates suitable semi-empirical equation will be more likely to be useful at large angles of attack. The information provided by this paper will be very much useful indesign stage of AUVs.