Directional Response of a B-Train Vehicle Combination Carrying Liquid Cargo

Abstract

Directional dynamics of a B-train tank vehicle is investigated by integrating the three-dimensional vehicle model to the dynamics associated with the movement of free surface of liquid within the partially filled tanks. The motion of the free surface of liquid due to instantaneous tank roll and lateral acceleration is computed assuming steady state fluid flow conditions. The influence of liquid motion on the dynamic response of the rearmost trailer is investigated for both constant and transient steer inputs, assuming constant forward speed. Directional response characteristics of the B-train tank vehicle are compared to those of an equivalent rigid cargo vehicle to demonstrate the destabilizing effects of the liquid movement within the tank vehicle. Directional response characteristics are further discussed for variation in weight density of liquid and thus the fill height, while the axle loads are held constant around maximum permissible values.