Technical feasibility of a pneumatically driven vehicle

Highlights: • All-air vehicle driving mechanism is introduced. • Experimental setup up with an air-driven motor is used. • Various load cycles are introduced and power transmission analyzed. In this work, the technical feasibility of an all-air vehicle is investigated. A test rig has been built for this purpose in order to assess the proposed system experimentally. The operating pressures selected are deliberately low to mitigate the heat generated/dissipated during charging and discharging of the air cylinders driving an air motor, respectively. The experimental setup consists of three cylinders charged up to 5 bar and operated via solenoid valves to control the discharge of the cylinders via a programmable logic controller. The operating modes vary according to the expected load demand on the vehicle during startup and also during cruise. The three cylinders are discharged in tandem if the demand calls for high power density, then they are operated sequentially to augment the operational range of the vehicle. A simple sprocket-chain mechanism is used for its simplicity in this proof-of-concept stage to better understand the parameters pertinent to vehicle operation, which will later be replaced by a continuously variable transmission (CVT) gear. The results show a great potential for such mode of transport, especially for vast locales, such as a hospital, golf course or a university campus, with top velocities estimated to be around 14 km/h velocities and driven sprocket powers of 0.7 hp. Other combinations of drive gear ratio and cylinder discharge sequences result in a wide range of output power and maximum speed possibilities.