Apparatus and method for determination of liquid mass
Inventors
Assignees
University of Alabama in Huntsville
Publication Number
US-12055427-B1
Publication Date
2024-08-06
Expiration Date
2035-03-13
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
The present disclosure generally pertains to devices and methods for determining propellant mass based on average measurements irrespective of the fluid orientation in a fuel tank. The device is useful in detecting fuel levels in tanks where the fuel is in motion, for instance in aircraft (i.e., undergoing varying acceleration maneuvers) or spacecraft (i.e., a microgravity environment). The devices and methods can also be used for determining the liquid in a surface tension screen liquid acquisition device (LAD), and particularly, the incipient breakdown as gas bubbles enter or are formed inside the LAD as the screen dries or heat transfer induces vaporization. The same basic electrode configuration can be used to stir the liquid to reduce thermal stratification and condense vapor bubbles.
Core Innovation
The invention is directed to devices and methods for determining the mass of a liquid such as a propellant within a tank, based on averaged capacitance measurements that are independent of the fluid's orientation. The invention is particularly useful for measuring fuel mass in environments where the liquid is in motion or distributed unpredictably, such as in aircraft during varying maneuvers or spacecraft operating in microgravity.
The disclosed system involves a tank with a liquid acquisition device (LAD), comprising a hollow tube and one or more electrodes within the tube. A capacitance measuring circuit detects capacitance levels between the electrodes and the tube wall, and a computing system converts these measurements to determine liquid mass. This approach also allows detection of vapor bubbles inside the LAD by monitoring for significant changes in the measured capacitance, addressing challenges present with conventional measurement devices.
A key feature is the ability to initiate agitation of the fluid inside the LAD using electrostatic forces generated by the electrodes when vapor bubbles are detected, thus helping eliminate bubbles, reduce temperature stratification, and maintain proper fluid acquisition. The system efficiently measures propellant mass both inside the general tank volume and within the LAD, providing accurate and reliable liquid mass determination even under challenging conditions like low gravity or sloshing.
Claims Coverage
The patent contains several independent claims, each addressing a unique set of inventive features pertaining to fluid mass determination, vapor bubble detection, and system operation.
System for vapor bubble detection and electrostatic agitation in a liquid acquisition device
The system includes a tank containing a fluid, a liquid acquisition device (LAD) with a hollow tube and one or more electrodes inside, a capacitance measuring circuit electrically connected to both the electrodes and the tube wall, and a computing system. The computing system detects vapor bubbles in the LAD based on the measured capacitance and initiates agitation of the fluid in the LAD via electrostatic forces from the electrodes upon bubble detection.
System with switchable voltage sources for dual operation modes
A system comprising a tank, LAD with an internal electrode, capacitance measuring circuit, computing system, first and second voltage sources delivering different voltage levels, and a switching element connected to the electrode. The switching element is controlled by the computing system: it applies the first voltage for measurement, and upon detection of a vapor bubble, switches to the second voltage to agitate the fluid electrostatically.
Method of detecting vapor bubbles and electrostatic agitation in a LAD
A method involving depositing fluid into a tank with an LAD containing one or more electrodes, measuring capacitance within the LAD, detecting vapor bubbles based on the capacitance, and initiating fluid agitation in the LAD with electrostatic forces from the electrodes when detection occurs.
Method for vapor bubble detection and switching agitation voltage in a LAD
A method comprising depositing fluid in a tank with an LAD and internal electrode, coupling two voltage sources of different levels to a switching element and the electrode, measuring capacitance within the LAD, detecting vapor bubbles based on the measurement, and, in response, controlling the switch to apply the second voltage and generate electrostatic agitation to condense bubbles in the LAD.
The independent claims collectively cover systems and methods for reliable detection of vapor bubbles in a LAD using capacitance measurements, and active mitigation of such bubbles through controlled electrostatic agitation, employing hardware and operation modes to provide accurate fluid mass determination.
Stated Advantages
Provides accurate measurements of liquid mass regardless of fluid orientation in the tank, even when the fluid is in motion or in microgravity environments.
Improves measurement accuracy particularly when fuel mass is low, which is a critical condition for propellant management.
Detects vapor bubbles and enables their elimination by electrostatic agitation, reducing the risk of engine or pump malfunctions due to bubble formation in the LAD.
Minimizes errors associated with conventional point sensors that can give false readings due to liquid adhering in microgravity.
Allows the determination of total mass in both the general tank volume and within a liquid acquisition device.
Reduces temperature stratification and aids in condensing vapor bubbles through agitation.
Documented Applications
Detecting fuel levels in tanks for aircraft during flight maneuvers where fuel is in motion.
Detecting fuel levels and propellant mass in spacecraft, especially in microgravity environments.
Determining liquid content and incipient breakdown in surface tension screen liquid acquisition devices (LADs).
Eliminating vapor bubbles inside LADs during fuel acquisition to prevent engine and pump damage.
Use in vehicles such as cars, trucks, sea vessels, or space vehicles where accurate fuel mass measurement is required despite fluid motion.
Interested in licensing this patent?