Experimental analysis of a planing monohull model during forward acceleration: part II - evaluation of an indirect method for applying thrust angle in the experiments

Most towing tank model tests conducted on planing hulls are not performed under self-propulsion conditions, and it is often not feasible to directly apply towing force at the corresponding point of action and along the thrust of the full-scale vessel. Therefore, it is essential to establish a well-defined method for accurately applying the thrust line in bare hull model tests using alternative loading solutions, such as CG shift, and understand how any deviation affects the model's running attitude and performance. This article presents an analysis of the dynamic equilibrium equations of motion for the model, considering various variables that can be used to adjust the thrust line in towing tank tests. The proposed formalism can aid in determining the external loading requirements in resistance tests. Finally, the article discusses the challenges and provides an error estimation for a simplified method of applying a constant thrust angle in the accelerated tests.