Increasing airframe fueldraulic system pressures and flow requirements have put severe demands on fuel system thermal management techniques. Heat loads from a variety of sources are constantly increasing the temperatures at which modern aircraft fuel systems are required to operate. Variable Displacement Vane Pump (VDVP) based systems are a solution to thermally constrained high pressure turbine engine fuel supply and fueldraulic actuation systems (i.e. variable engine nozzle and/or variable engine geometry). VDVPs offer several benefits including exceptional thermal efficiency, fast response and contamination resistance comparable to legacy systems. Utilizing a simple pumping design in conjunction with recent advances in material and bearing technology, the VDVP has demonstrated high thermal efficiency for flow turndowns up to 100:1 in a range of displacements from 5 gpm (small engines) to 120 gpm (large turbofans). Based on testing to date, VDVP systems also have potential for high-pressure fueldraulics and are capable of cavitation-free operation for extended periods of time. The VDVP is easy to operate in flow or pressure control loops and can easily meet the slew requirements of modern engines. With over 15000 hours of testing under various pressure, flow and fuel temperature conditions this technology is approaching readiness for integrated test with some challenging gas turbine engine applications. The intent of this paper is to share the system level thermal management benefits, basic design principles, test data, and potential applications of the Goodrich VDVP.
Scheme of partial unloading of the plate of a high-pressure vane pump