System and Method for Fluid Dynamic Mass Gauging

The capacitive micro-gravity fluid mass gauge with spatial regularization is a sensor that can be outfitted to propellant vessels and can provide a determination of the mass of liquid and gas inside the vessel volume with a determinable level of accuracy. The sensor consists of 1) a number of discrete electrodes that are installed to the inner surface of the vessel wall, 2) signal generating, digitizing, signal conditioning, and general support (e.g., power supply) electronics, 3) electrical connections between the electrodes and the electronics, and 4) the algorithm used to turn the set of capacitance measurements (i.e., the capacitance matrix) into a volume fraction. The electronics generate and apply a sinusoid to a single electrode, and then the electronics measure the charge on all other electrodes. Capacitance is simply the charge divided by the voltage. This is repeated for all electrodes, without repeating duplicates. For a vessel with a fixed volume, the volume fraction can be converted to the mass fraction using the Ideal Gas Law so long as the fluid constituents, temperature, and pressure are known.

Unlike commercial turbine and Venturi-type sensors, which are flow intrusive and prone to high error rates, NASA's new flow sensor technology uses an optical technique to precisely measure the physical characteristics of a liquid flowing within a pipe. It generates a reading of the flows density, which provides a highly accurate mass flow measurement when combined with flow velocity data from a second optical sensor. NASA's sensor technology provides both a void fraction measurement, which is a measurement of the instantaneous gas/liquid percentage of a static volume and a quality measurement, which is the fraction of flow that is vapor as part of a total mass flow. It also provides a direct measurement of the gas/liquid concentration within the flow, making it suited for real-time measurement of multi-phase flows. The technology was originally developed to accurately determine the flow rates and tank levels of multi-phase cryogenic fuels used on various NASA vehicles including the Space Shuttle and in ground-based propulsion testing. It can also be used for a wide range of gas/liquid ratios, flows with complex cross sectional profiles, flows containing bubbles or quasi-solids, and essentially any liquid, gas, or multi-phase flow that can be optically characterized. Because it is insensitive to position, the new technology also has potential for use in zero-gravity tank level sensors.

Armstrong has developed a robust fiber optic–based sensing technology that offers extraordinary accuracy in liquid level measurements. The sensing system uses fiber optic Bragg sensors located along a single fiber optic cable. These sensors actively discern between the liquid and gas states along a continuous fiber and can accurately pinpoint the liquid level. How It Works The technology uses a resistive heater wire bundled with the optical fiber. The heater is pulsed to induce a local temperature change along the fiber, and the fiber Bragg grating data is used to monitor the subsequent cooling of the fiber. The length of fiber in the liquid cools more rapidly than the portion of the fiber in the gas above the liquid. The measurement system accurately establishes the location of this transition to within 1/4-inch. Why It Is Better Armstrong's liquid level sensing technology was originally developed to measure cryogenic liquid levels in rockets, and it represents a significant advancement in the state of the art in this application. Conventional methods for measuring cryogenic liquid levels rely on cryogenic diodes strategically placed along a rod or rack. The diodes are mounted in pre-selected, relatively widely spaced positions along the length of a rod; this configuration provides limited, imprecise data. Furthermore, each diode on the rod has two wires associated with it, which means a single system may require a large number of wires, making installation, connectivity, and instrumentation cumbersome. Armstrong's novel technology provides liquid measurements with much greater precision, achieving measurements at 1/4-inch intervals. Furthermore, the streamlined system uses just two wires, which greatly simplifies installation and instrumentation. Due to its extraordinary accuracy and ease of use, Armstrong's measurement system offers important advantages for a wide range of applications beyond cryogenic liquids. In Addition Researchers have developed a new manufacturing process that improves the ability of fiber optic sensing systems to measure temperature and liquid levels when operating in humid environments. The process involves eliminating moisture from the optical fiber coating, then completing the sensor assembly within humidity-controlled conditions. The resulting sensor hardware provides precise and accurate measurements even when operating in a humid environment. For more information about the full portfolio of FOSS technologies, see DRC-TOPS-37 or visit https://technology-afrc.ndc.nasa.gov/featurestory/fiber-optic-sensing

NASA MSFC&#8217s Fluid-Filled Frequency-Tunable Mass Damper (FTMD) technology implements a fluid-based mitigation system where the working mass is all or a portion of the fluid mass that is contained within the geometric configuration of either a channel, pipe, tube, duct and/or similar type structure. A compressible mechanism attached at one end of the geometric configuration structure enables minor adjustments that can produce large effects on the frequency and/or response attributes of the mitigation system. Existing fluid-based technologies like Tuned Liquid Dampers (TLD) and Tuned Liquid Column Dampers (TLCD) rely upon the geometry of a container to establish mitigation frequency and internal fluid loss mechanisms to set the fundamental mitigation attributes. The FTMD offers an innovative replacement since the frequency of mitigation and mitigation attributes are established by the compressible mechanism at the end of the container. This allows for simple alterations of the compressible mechanism to make frequency adjustments with relative ease and quickness. FTMDs were recently successfully installed on a building in Brooklyn, NYC as a replacement for a metallic TMD, and on a semi-submersible marine-based wind turbine in Maine. The FTMD technology is available for non-exclusive licensing and partially-exclusive licensing (outside of building construction over 300 feet).

The MOD platform technology represents a small, lightweight, and reproducible in vitro drug screening model that could inexpensively mimic different mammalian tissues for a multitude of applications. The technology is automated and imposes minimal demands for resources (power, analytes, and fluids). The MOD technology uses titanium isopropoxide to bond a microscale support to a substrate and uses biopatterning and 3D tissue bioprinting on a microfluidic microchip to eliminate variations in local seeding density while minimizing selection pressure. With the MOD, pharmaceutical companies can test more candidates and concentrate on those with more promise therefore, reducing R&D overall cost. This innovation overcomes major disadvantages of conventional in vitro and in vivo experimentation for purposes of investigating effects of medicines, toxins, and possibly other foreign substances. For example, the MOD platform technology could host life-like miniature assemblies of human cells and the effects observed in tests performed could potentially be extrapolated more readily to humans than could effects observed in conventional in vivo cell cultures, making it possible to reduce or eliminate experimentation on animals. The automated NASA developed technology with minimal footprint and power requirements, micro-volumes of fluids and waste, high throughput and parallel analyses on the same chip, could advance the research and development for new drugs and materials.