Granular scaling laws for helically driven dynamics

We develop scaling laws for the mobility of screw-propelled vehicles on granular media and use experimental and computational approaches to verify those. A modular screw propelled vehicle is, therefore, designed for testing the accuracy of this helical granular scaling law in predicting vehicle translational velocity and power. Experimental agreement for prediction of power (3–9% error) and translational velocity (2–12% error) are observed. A similar set of geometries is subjected to multibody dynamics and discrete element method cosimulations of Earth and lunar gravity to verify a gravity-dependent subset of the scaling laws. These simulations show agreement (under 5% error for all sets) and support law validity for gravity between Earth and lunar magnitude. These results support further expansion of granular scaling models to enable prediction for vehicle-terrain dynamics for a variety of environments and geometries.