Measured and predicted response of a submerged towed sonar array to maneuvering input

There exists a necessity to increase a helicopter pilot´s safety during mine countermeasure operations. Models have been developed for scenarios involving a cable that is fully submerged in either air or water, but there has been very little testing when the cable is partially submerged. This change in fluid type along the length of the cable has a significant impact on the stability and drag forces that has not yet been extensively studied. A series of experimental investigations examining speed, acceleration, length of cable and path of motion were paired with predictions from a simulation for the purpose of developing a predictive tool. These tests characterized the stability of the body, indicating that acceleration is a governing factor in the operability of the towed sonar. The simulation developed to predict the behavior of the helicopter towed submerged body predicts the fundamental behavior of the body, but does not capture hydrodynamic instabilities that result in the body leaving the water.