Combat Vehicle Engine Selection Methodology Based On Vehicle Integration Considerations 2005-01-1545

Past experience has shown that the power density of an engine itself is not a sufficient guide to determine whether it will meet the power density needs of the intended combat vehicle application. The real need is for the complete propulsion system to be power dense. Here the definition of the propulsion system includes the engine, transmission, cooling system, air filtration system, intake and exhaust ducting, controls, accessories, batteries, fuel system and final drives. The power pack is a subset of the propulsion system and consists of that part of the propulsion system that would be lifted out of the vehicle for service or replacement and would typically consist of at least the engine, and transmission, cooling system, and power pack controls and ideally would also include the air filtration system and accessory drives.

Engine operating characteristics will directly impact power density for some propulsion system items. Engine air flow characteristics will impact air filtration and intake and exhaust space and weight claims, engine heat rejection and operating fluid temperatures will impact cooling system size and parasitic fan power required and engine fuel consumption characteristics will impact fuel system space for a given range or mission requirement. These characteristics as well as the physical nature, shape, and configuration of the engine will influence the power density of the overall propulsion system. The purpose of this paper will be to look at the issues of power density for combat vehicle propulsion and look at a methodology to evaluate engine candidates for such applications based on an overall propulsion system power density perspective.