A tracer particle spreading device for a boundary layer flow visualization experiment based on a flat plate includes a tracer particle generator, a smoke storage box, and a wall-surface particle distribution box. Fume and oil are pressurized by a micro pump and flows into a heating pipe to be heated and vaporized, and then is ejected from a nozzle to form tracer particles. The tracer particles enter the smoke storage box via a smoke guiding tube. An axial flow fan is mounted on a wall surface of the smoke storage box. The tracer particles enter a cavity of the wall-surface particle distribution box via the smoke guiding tube, and the tracer particles are rectified by a rectifying plate and ejected from a spreading slit. An outlet of the spreading slit is at an angle of 15° with respect to an experiment flat plate.

A tracer particle spreading device for a boundary layer flow visualization experiment based on a flat plate includes a tracer particle generator, a smoke storage box, and a wall-surface particle distribution box. Fume and oil are pressurized by a micro pump and flows into a heating pipe to be heated and vaporized, and then is ejected from a nozzle to form tracer particles. The tracer particles enter the smoke storage box via a smoke guiding tube. An axial flow fan is mounted on a wall surface of the smoke storage box. The tracer particles enter a cavity of the wall-surface particle distribution box via the smoke guiding tube, and the tracer particles are rectified by a rectifying plate and ejected from a spreading slit. An outlet of the spreading slit is at an angle of 15° with respect to an experiment flat plate.

Disclosed herein is a technique of configuring flexible photovoltaic tracker systems with high damping and low angle stow positions. Under dynamic environmental loads implementing a high amount of damping (e.g., greater than 25% of critical damping, greater than 50% of critical damping) or a very high amount of damping (e.g., 100% or greater of critical damping, infinite damping) enables the flexible tracker system to prevent problematic aeroelastic behaviors while positioned in a low stow angle. The disclosed technique is further applied to a prototyping process during wind tunnel testing.

Disclosed herein is a technique of configuring flexible photovoltaic tracker systems with high damping and low angle stow positions. Under dynamic environmental loads implementing a high amount of damping (e.g., greater than 25% of critical damping, greater than 50% of critical damping) or a very high amount of damping (e.g., 100% or greater of critical damping, infinite damping) enables the flexible tracker system to prevent problematic aeroelastic behaviors while positioned in a low stow angle. The disclosed technique is further applied to a prototyping process during wind tunnel testing.

Disclosed herein is a technique of configuring flexible photovoltaic tracker systems with high damping and low angle stow positions. Under dynamic environmental loads implementing a high amount of damping (e.g., greater than 25% of critical damping, greater than 50% of critical damping) or a very high amount of damping (e.g., 100% or greater of critical damping, infinite damping) enables the flexible tracker system to prevent problematic aeroelastic behaviors while positioned in a low stow angle. The disclosed technique is further applied to a prototyping process during wind tunnel testing.

Disclosed herein is a technique of configuring flexible photovoltaic tracker systems with high damping and low angle stow positions. Under dynamic environmental loads implementing a high amount of damping (e.g., greater than 25% of critical damping, greater than 50% of critical damping) or a very high amount of damping (e.g., 100% or greater of critical damping, infinite damping) enables the flexible tracker system to prevent problematic aeroelastic behaviors while positioned in a low stow angle. The disclosed technique is further applied to a prototyping process during wind tunnel testing.

A stretchable bidirectional capacitive pressure sensor (20) comprising: a first elastomeric sheet (22) made from a dielectric material, with a series of conductor lines (221) located on or in the first elastomeric sheet; a second elastomeric sheet (28) made from a dielectric material, with a series of conductor lines (261) located on or in the second elastomeric sheet; wherein the conductor lines of the first elastomeric sheet are substantially orthogonal to the conductor lines of the second elastomeric sheet; a microstructure comprising a plurality of elastomeric pillars (241) made from a dielectric material, disposed between the elastomeric sheets; wherein the microstructure is bonded to both the first and second elastomeric sheets so that the bidirectional sensor can register positive and negative pressure by the movement of the first and second elastomeric sheets. A further aspect of the invention discloses a method of collecting data related to fluid flow over an object by using a two-dimensional capacitive pressure sensor.

A stretchable bidirectional capacitive pressure sensor (20) comprising: a first elastomeric sheet (22) made from a dielectric material, with a series of conductor lines (221) located on or in the first elastomeric sheet; a second elastomeric sheet (28) made from a dielectric material, with a series of conductor lines (261) located on or in the second elastomeric sheet; wherein the conductor lines of the first elastomeric sheet are substantially orthogonal to the conductor lines of the second elastomeric sheet; a microstructure comprising a plurality of elastomeric pillars (241) made from a dielectric material, disposed between the elastomeric sheets; wherein the microstructure is bonded to both the first and second elastomeric sheets so that the bidirectional sensor can register positive and negative pressure by the movement of the first and second elastomeric sheets. A further aspect of the invention discloses a method of collecting data related to fluid flow over an object by using a two-dimensional capacitive pressure sensor.

The present invention provides large-amplitude vertical-torsional coupled free vibration testing device for bridges in natural winds, which comprises a rigid model, light-weight high-strength thin strings, linear extension springs, a rigid framework, spring protection tubes, a turntable, a rigid column, a motor, heavy blocks, and rigid thin circular rods. Based on the device, free vibration tests of a bridge deck rigid model can be carried out in natural wind with good conditions, and hence the large-scale wind tunnel device is no longer required. The scaling ratio of the rigid model is no longer limited by the wind tunnel size as in a traditional test, and the scaling ratio can be much larger. Compared with traditional wind tunnel test, the device is more suitable for large-amplitude vibration tests since it can reduce the geometrical nonlinearities of the extension springs and the blocking ratio.

A method of evaluating integrated running energy of a vehicle in a wind tunnel may include estimating change in fuel efficiency according to change of vehicle parts thereby facilitating precise measurement of running energy.