Abstract: A filter screen includes a plate body with an upstream surface, an opposed downstream surface, and an array of apertures extending between the upstream surface and the downstream surface. A polytetrafluoroethylene-based layer overlays the upstream surface between apertures of the aperture array, the polytetrafluorethylene-based layer being conformally disposed over the upstream surface of the plate body and spanning the upstream surface between the apertures of the aperture array to slow deposition of carbonaceous deposits on the filter screen.

Abstract: A fuel actuation system may comprise a servo valve (SV) including a torque motor and at least one screen, a metering valve (MV) fluidly connected to the SV, and an electronic engine control (EEC) operatively connected to the SV. The EEC may be configured and disposed to determine a travel time of the MV, a travel distance of the MV, a pressure of a fuel, and/or a temperature of the fuel, generate at least one of a travel time history, a travel distance history, a fuel temperature history, and a fuel pressure history, and determine a level of degradation of the fuel actuation system based on the at least one of the travel time history, the travel distance history, the fuel temperature history, or the fuel pressure history.

Abstract: A system and method for the calculation of a fuel lacquer index using environmental monitoring is disclosed. The system and method may comprise: capturing a fuel temperature data; determining a fuel quality rating; calculating a volumetric fuel flow; calculating a fuel filter differential pressure; and calculating a fuel lacquer index. The fuel lacquer index may be calculated as a percentage value based upon the fuel temperature data, the fuel quality rating, the volumetric fuel flow, and the fuel filter differential pressure.

Abstract: A fuel actuation system may comprise a servo valve (SV) including a torque motor and at least one screen, a metering valve (MV) fluidly connected to the SV, and an electronic engine control (EEC) operatively connected to the SV. The EEC may be configured and disposed to determine a travel time of the MV, a travel distance of the MV, a pressure of a fuel, and/or a temperature of the fuel, generate at least one of a travel time history, a travel distance history, a fuel temperature history, and a fuel pressure history, and determine a level of degradation of the fuel actuation system based on the at least one of the travel time history, the travel distance history, the fuel temperature history, or the fuel pressure history.

Abstract: Systems and methods for monitoring fuel actuation system health are described herein. A method for monitoring fuel actuation system health may comprise: moving a metering valve from a first position to a second position; detecting a first travel distance of the metering valve; storing the first travel distance of the metering valve to memory to generate a first travel distance history; and determining a level of degradation of the fuel actuation system based on at least the first travel distance history.

Abstract: A filter screen includes a plate body with an upstream surface, an opposed downstream surface, and an array of apertures extending between the upstream surface and the downstream surface. A polytetrafluoroethylene-based layer overlays the upstream surface between apertures of the aperture array, the polytetrafluorethylene-based layer being conformally disposed over the upstream surface of the plate body and spanning the upstream surface between the apertures of the aperture array to slow deposition of carbonaceous deposits on the filter screen.

Abstract: Systems and methods for monitoring fuel actuation system health are described herein. A method for monitoring fuel actuation system health may comprise: moving a metering valve from a first position to a second position; detecting a first travel distance of the metering valve; storing the first travel distance of the metering valve to memory to generate a first travel distance history; and determining a level of degradation of the fuel actuation system based on at least the first travel distance history.

Abstract: A system and method for the calculation of a fuel lacquer index using environmental monitoring is disclosed. The system and method may comprise: capturing a fuel temperature data; determining a fuel quality rating; calculating a volumetric fuel flow; calculating a fuel filter differential pressure; and calculating a fuel lacquer index. The fuel lacquer index may be calculated as a percentage value based upon the fuel temperature data, the fuel quality rating, the volumetric fuel flow, and the fuel filter differential pressure.

Abstract: A fuzzy logic based fuel flow selection (control) system is presented. Control loops are used to provide desired engine fuel flow control. These loops receive engine operating parameters and provide fuel flow command values in accordance with corresponding transfer functions. These command values are presented to selection logic, which provides a command value based on outputs of the control loops. The command value integrated by a common integrator to provide and integrated command value which is the fuel flow command that is presented to a fuel metering unit at the engine. Each loop has a level of authority assigned to it, which is computed in terms of fuzzy rules and membership functions. Thus at any given moment, more than one loop may be in control to differing levels of authority, whereby the present invention provides a smoother transition between loops competing for control with an attendant increase in system performance.