A fluid tank comprising can include an outer housing comprising a housing volume, a first fluid bladder positioned within the housing volume, and a second fluid bladder positioned within the housing volume. The first fluid bladder can comprise a first conduit and the second fluid bladder can comprise a second conduit. The first fluid bladder can be configured to release fluid through the first conduit in response to introduction of fluid into the second fluid bladder via the second conduit. The housing volume can be maintained at a substantially constant pressure when fluid is released from the first fluid bladder through the first conduit and fluid is introduced into the second fluid bladder through the second conduit.

Methods and systems are provided for diagnosing leaks/degradation in a fuel system. In one example, a system for a vehicle may comprise a variable volume device disposed within a fuel tank; an atmospheric port of the variable volume device fluidly coupled to a vent line upstream of a hydrocarbon sensor housed in the vent line, the vent line coupling a fuel vapor canister to atmosphere; and a controller storing instructions for monitoring output of the hydrocarbon sensor; and generating an indication of a degradation in the variable volume device based on the monitored hydrocarbon sensor. In this way, it is possible to effectively detect a degradation/leak in the variable volume device with minimal specialized components in the fuel system.

A fuel tank structure includes: a fuel tank that is installed in an automobile and that accommodates fuel; a bag-shaped member that is fixed to a ceiling portion of an interior of the fuel tank, and whose state of contact with a liquid surface of fuel accommodated in the fuel tank is maintained due to the bag-shaped member inflating or deflating in accordance with a height of the liquid surface; a temperature sensor that senses a temperature of the fuel or evaporated fuel that is within the fuel tank; and a cooling wind introducing section that introduces cooling wind into an interior of the bag-shaped member in a case in which the temperature of the fuel or the evaporated fuel detected by the temperature sensor becomes higher than a predetermined temperature.

An enclosed volume is provided for performing operations in space, or on any astronomical object, in a manner separated from aspects of the external environment. The enclosed volume can be a flexible container for a satellite. The enclosed volume can include a membrane having a fluid barrier layer and being configured to contain a propellant gas or fluid; and an expulsion device configured to expel material from the membrane. In a stowed configuration, the flexible container is contained within the satellite, and in a deployed configuration, the flexible container extends away from the satellite. The flexible container can inflate from one shape, in the undeployed configuration, to another shape, in a deployed configuration. The other shape can be toroidal or other appropriate shapes. The flexible container can provide bipropellant, blowdown, and gas/fluid metering functionality. Entertainment and game play can be enabled by the enclosed volume involving robots and other devices.

An operating fluid container for a motor vehicle for accommodating an operating fluid. The operating fluid container has a compensation container that is at least indirectly fluidically connected to the atmosphere (ATM). The operating fluid container has the following features: the compensation container is situated within the operating fluid container in such a way that an outer surface of a compensation container upper shell is situated opposite from an inner surface of an operating fluid container upper shell; in the event of positive pressure in the operating fluid container relative to the atmosphere, a compensation container volume decreases; and in the event of negative pressure in the operating fluid container relative to the atmosphere, the compensation container volume increases. The operating fluid container is characterized in that the compensation container upper shell opposite from the operating fluid container upper shell has a shape, at least in sections, that is complementary to the operating fluid container upper shell.

An enclosed volume is provided for performing operations in space, or on any astronomical object, in a manner separated from aspects of the external environment. The enclosed volume can be a flexible container for a satellite. The enclosed volume can include a membrane having a fluid barrier layer and being configured to contain a propellant gas or fluid; and an expulsion device configured to expel material from the membrane. In a stowed configuration, the flexible container is contained within the satellite, and in a deployed configuration, the flexible container extends away from the satellite. The flexible container can inflate from one shape, in the undeployed configuration, to another shape, in a deployed configuration. The other shape can be toroidal or other appropriate shapes. The flexible container can provide bipropellant, blowdown, and gas/fluid metering functionality. Entertainment and game play can be enabled by the enclosed volume involving robots and other devices.

Methods and systems are provided for diagnosing leaks/degradation in a fuel system. In one example, a system for a vehicle may comprise a variable volume device disposed within a fuel tank; an atmospheric port of the variable volume device fluidly coupled to a vent line upstream of a hydrocarbon sensor housed in the vent line, the vent line coupling a fuel vapor canister to atmosphere; and a controller storing instructions for monitoring output of the hydrocarbon sensor; and generating an indication of a degradation in the variable volume device based on the monitored hydrocarbon sensor. In this way, it is possible to effectively detect a degradation/leak in the variable volume device with minimal specialized components in the fuel system.

An enclosed volume is provided for performing operations in space, or on any astronomical object, in a manner separated from aspects of the external environment. The enclosed volume can be a flexible container for a satellite. The enclosed volume can include a membrane having a fluid barrier layer and being configured to contain a propellant gas or fluid; and an expulsion device configured to expel material from the membrane. In a stowed configuration, the flexible container is contained within the satellite, and in a deployed configuration, the flexible container extends away from the satellite. The flexible container can inflate from one shape, in the undeployed configuration, to another shape, in a deployed configuration. The other shape can be toroidal or other appropriate shapes. The flexible container can provide bipropellant, blowdown, and gas/fluid metering functionality. Entertainment and game play can be enabled by the enclosed volume involving robots and other devices.

An enclosed volume is provided for performing operations in space, or on any astronomical object, in a manner separated from aspects of the external environment. The enclosed volume can be a flexible container for a satellite. The enclosed volume can include a membrane having a fluid barrier layer and being configured to contain a propellant gas or fluid; and an expulsion device configured to expel material from the membrane. In a stowed configuration, the flexible container is contained within the satellite, and in a deployed configuration, the flexible container extends away from the satellite. The flexible container can inflate from one shape, in the undeployed configuration, to another shape, in a deployed configuration. The other shape can be toroidal or other appropriate shapes. The flexible container can provide bipropellant, blowdown, and gas/fluid metering functionality. Entertainment and game play can be enabled by the enclosed volume involving robots and other devices.

A tank system of a motor vehicle includes a volume-modifying element, which is provided in the interior of the fuel tank at least substantially above the liquid level and which is designed as a deformable bag, which forms a compensation volume connected to the environment, and includes a valve assembly, which closes under the control of a float during the filling of the fuel tank and thus brings about a maximum fill level in the fuel tank. A measure is provided for eliminating an effect of the volume-modifying element on the maximum fill level height. This measure can be that the volume-modifying element is arranged in the fuel tank such that, when the vehicle is standing on a horizontal surface, the top side of the volume-modifying element is not significantly above the fuel fill level at which the valve assembly closes in the vertical axis direction. Other measures include, for example, a controllable valve, which is provided in the connection between the compensation volume of the volume-modifying element and the environment and which is actuated in the closing direction when the fill level rising during the filling process has reached the maximum fill level height.