Abstract: A tapered groove width heat pipe is disclosed, including a tube having an internal surface, a first end, a second end, and a central axis. A plurality of groove walls on the internal surface define a plurality of trapezoidal grooves. Each groove wall has a proximal width closest to the central axis and a distal width furthest from the central axis, the proximal width of a portion of each groove wall tapering gradually between the first end and the second end.

Abstract: An example method for installing optical sensors for a fuel level measurement system includes mounting a plurality of fittings through a wall of a fuel tank, positioning a plurality of optical sensors within the plurality of fittings and a respective optical sensor includes a first pressure sensing end inserted through the fitting and internally into the fuel tank and a second end extending externally from the fuel tank, and mounting an optical fiber bundle external to the fuel tank. The optical fiber bundle has an optical fiber connected to each of the plurality of optical sensors for guiding light to each of the plurality of optical sensors.

Abstract: A tapered groove width heat pipe is disclosed, including a tube having an internal surface, a first end, a second end, and a central axis. A plurality of groove walls on the internal surface define a plurality of trapezoidal grooves. Each groove wall has a proximal width closest to the central axis and a distal width furthest from the central axis, the proximal width of a portion of each groove wall tapering gradually between the first end and the second end.

Abstract: An example fuel quantity indicating system includes a fuel tank, optical sensors mounted inside the fuel tank that each include a sensor chip and a diaphragm that deflects when ambient pressure differs from a reference pressure of the sensor chip, an optical fiber bundle that has an optical fiber connected to each of the optical sensors for guiding light to each of the optical sensors, and a processor connected to the optical fiber bundle for receiving outputs of the optical sensors indicative of respective pressures, and for determining a fuel level measurement of the fuel tank based on the outputs of the optical sensors.

Abstract: An example system includes a fuel tank, fittings mounted through a wall of the fuel tank, and optical sensors positioned within the fittings. A respective optical sensor includes a first pressure sensing end inserted through a fitting and internally into the fuel tank and a second end extending externally from the fuel tank. The system also includes an optical fiber bundle mounted external to the fuel tank, and having an optical fiber connected to each of the plurality of optical sensors for guiding light to each of the plurality of optical sensors.

Abstract: An example system includes a fuel tank, fittings mounted through a wall of the fuel tank, and optical sensors positioned within the fittings. A respective optical sensor includes a first pressure sensing end inserted through a fitting and internally into the fuel tank and a second end extending externally from the fuel tank. The system also includes an optical fiber bundle mounted external to the fuel tank, and having an optical fiber connected to each of the plurality of optical sensors for guiding light to each of the plurality of optical sensors.

Abstract: An example fuel quantity indicating system includes a fuel tank, optical sensors mounted inside the fuel tank that each include a sensor chip and a diaphragm that deflects when ambient pressure differs from a reference pressure of the sensor chip, an optical fiber bundle that has an optical fiber connected to each of the optical sensors for guiding light to each of the optical sensors, and a processor connected to the optical fiber bundle for receiving outputs of the optical sensors indicative of respective pressures, and for determining a fuel level measurement of the fuel tank based on the outputs of the optical sensors.

Abstract: An example fuel quantity indicating system includes a fuel tank, optical sensors mounted inside the fuel tank that each include a sensor chip and a diaphragm that deflects when ambient pressure differs from a reference pressure of the sensor chip, an optical fiber bundle that has an optical fiber connected to each of the optical sensors for guiding light to each of the optical sensors, and a processor connected to the optical fiber bundle for receiving outputs of the optical sensors indicative of respective pressures, and for determining a fuel level measurement of the fuel tank based on the outputs of the optical sensors.

Abstract: An example system includes a fuel tank, fittings mounted through a wall of the fuel tank, and optical sensors positioned within the fittings. A respective optical sensor includes a first pressure sensing end inserted through a fitting and internally into the fuel tank and a second end extending externally from the fuel tank. The system also includes an optical fiber bundle mounted external to the fuel tank, and having an optical fiber connected to each of the plurality of optical sensors for guiding light to each of the plurality of optical sensors.

Abstract: An example fuel quantity indicating system includes a fuel tank, optical sensors mounted inside the fuel tank that each include a sensor chip and a diaphragm that deflects when ambient pressure differs from a reference pressure of the sensor chip, an optical fiber bundle that has an optical fiber connected to each of the optical sensors for guiding light to each of the optical sensors, and a processor connected to the optical fiber bundle for receiving outputs of the optical sensors indicative of respective pressures, and for determining a fuel level measurement of the fuel tank based on the outputs of the optical sensors.