Dynamic Stability of the Hybrid Airship Influenced by Added Mass Effect

This paper first derives the second-order approximation of force and moment based on the definition of added mass and stability derivatives. Further, it establishes a small perturbation model for high-altitude hybrid airships. Subsequently, a typical hybrid airship’s added mass parameters and stability derivatives are calculated using the computational fluid dynamics method. Based on the calculation results and the dynamic model, linear system analysis theory is applied to calculate and compare the eigenvalues of the state matrix and the step response of the system with the added mass effect. The results indicate that the stability of the hybrid airship remains unaffected by the added mass effect. In contrast, its control is significantly influenced, with a notable difference of approximately 23.7% in the steady-state value of the velocity step response between the two conditions. The method proposed in this paper can provide theoretical support for the design of hybrid airships.