Mobile tunnels may be provided on trailers or in association with one or more other vehicles. A mobile tunnel may be towed or otherwise accelerated to a sufficient velocity, thereby causing a fluid such as air or seawater to travel above, below and around the tunnel. The fluid may be diverted into the tunnel and caused to pass over a test object such as an unmanned aerial vehicle or unmanned undersea vehicle within the tunnel, thereby enabling aerodynamic testing or hydrodynamic testing of the test object to be performed. Additionally, one or more materials may be injected into the fluid, thereby enabling destructive testing of the test object to be performed.

Mobile tunnels may be provided on trailers or in association with one or more other vehicles. A mobile tunnel may be towed or otherwise accelerated to a sufficient velocity, thereby causing a fluid such as air or seawater to travel above, below and around the tunnel. The fluid may be diverted into the tunnel and caused to pass over a test object such as an unmanned aerial vehicle or unmanned undersea vehicle within the tunnel, thereby enabling aerodynamic testing or hydrodynamic testing of the test object to be performed. Additionally, one or more materials may be injected into the fluid, thereby enabling destructive testing of the test object to be performed.

A tunable mass-damping apparatus may include a housing having an interior surface, an interior volume containing a gas, and an axis. The housing may be configured to be coupled to a wind tunnel model. The mass-damping apparatus may include a mass configured to move back and forth in the interior volume along the axis. The mass may be configured to make an airtight seal with the interior surface of the housing, thereby dividing the interior volume into an upper chamber and a lower chamber. The mass-damping apparatus may include a passage through the mass fluidly connecting the chambers and at least one spring configured to exert a position-dependent force upon the mass. The spring may be characterized by a spring constant chosen based on a natural frequency of a support structure of the wind tunnel model.

A tunable mass-damping apparatus may include a housing having an interior surface, an interior volume containing a gas, and an axis. The housing may be configured to be coupled to a wind tunnel model. The mass-damping apparatus may include a mass configured to move back and forth in the interior volume along the axis. The mass may be configured to make an airtight seal with the interior surface of the housing, thereby dividing the interior volume into an upper chamber and a lower chamber. The mass-damping apparatus may include a passage through the mass fluidly connecting the chambers and at least one spring configured to exert a position-dependent force upon the mass. The spring may be characterized by a spring constant chosen based on a natural frequency of a support structure of the wind tunnel model.

An assembly quality detection device and a method for a wind screen cleaning system based on streamline pattern, includes a main body of a test bench and a detection system. The main body of the test bench includes a test bench rack and a cleaning centrifugal fan; the inside of the test bench rack is provided with a cleaning space. The detection system includes a smoke generation and transmission device, a two-degree-of-freedom smoke fixed-point release mechanism, a high-speed image acquisition system and a control system. A fixed base is installed on the upper end of the outlet of the cleaning centrifugal fan, a linear moving guide rail device is installed on the fixed base, the linear moving guide rail device is equipped with a moving slider, the moving slider is installed with a rotating mechanism, the rotating mechanism output end is provided with a smoke releasing duct, the smoke releasing duct is communicated with the smoke generation and transmission device. The detection device and method can test the manufacturing and assembly quality of the cleaning system of the combine harvester by combining the characteristics of wind tunnel streamline pattern with image processing and corresponding mathematical operation.

An assembly quality detection device and a method for a wind screen cleaning system based on streamline pattern, includes a main body of a test bench and a detection system. The main body of the test bench includes a test bench rack and a cleaning centrifugal fan; the inside of the test bench rack is provided with a cleaning space. The detection system includes a smoke generation and transmission device, a two-degree-of-freedom smoke fixed-point release mechanism, a high-speed image acquisition system and a control system. A fixed base is installed on the upper end of the outlet of the cleaning centrifugal fan, a linear moving guide rail device is installed on the fixed base, the linear moving guide rail device is equipped with a moving slider, the moving slider is installed with a rotating mechanism, the rotating mechanism output end is provided with a smoke releasing duct, the smoke releasing duct is communicated with the smoke generation and transmission device. The detection device and method can test the manufacturing and assembly quality of the cleaning system of the combine harvester by combining the characteristics of wind tunnel streamline pattern with image processing and corresponding mathematical operation.

A wind tunnel for stable sustained human flight for research or recreation, including a tunnel including first and second portions having first and second central axes, respectively, and a fan to create an air flow in the test section. The second portion is a test section. The first and second central axes are arranged at a first angle with respect to each other. The second central axis is at a second angle of 5°-85° with respect to a horizontal plane. A safety system for an inclined wind tunnel for stable sustained human flight is provided, including an inclined test section of the wind tunnel that is arranged at an angle of 5°-85° with respect to a horizontal plane, a fan to create an air flow in the test section directed from an upstream end towards a downstream end thereof, and a delimiting arrangement arranged at the test section for preventing a person using the test section from leaving it.

A wind tunnel for stable sustained human flight for research or recreation, including a tunnel including first and second portions having first and second central axes, respectively, and a fan to create an air flow in the test section. The second portion is a test section. The first and second central axes are arranged at a first angle with respect to each other. The second central axis is at a second angle of 5°-85° with respect to a horizontal plane. A safety system for an inclined wind tunnel for stable sustained human flight is provided, including an inclined test section of the wind tunnel that is arranged at an angle of 5°-85° with respect to a horizontal plane, a fan to create an air flow in the test section directed from an upstream end towards a downstream end thereof, and a delimiting arrangement arranged at the test section for preventing a person using the test section from leaving it.

A test cell for an aircraft turbojet, wherein the test cell comprises a U-shaped configuration, with a passageway in the form of an elongated corridor, an inlet chimney, and an outlet chimney. The corridor includes a securing area with a securing arm for holding the turbojet during its test. The passageway furthermore reveals an upstream shutter and a downstream shutter, the two shutters including one pivoting flap or a series of pivoting flaps. In the event of a fire, the shutters close due to autonomous return means. Gravity allows the flap(s) to come down to the closed position and to confine the turbojet in order to rapidly stifle the fire.

A parameter similarity method for test simulation conditions of an aerodynamic heating environment is disclosed. With respect to the requirement that the adiabatic wall enthalpy and the cold-wall heat flux are equal in the simulation test of the aerodynamic heating environment, a method that can ensure the similarity of ground test parameters and flight parameters without the equal adiabatic wall enthalpy is proposed, and solves the problems of relying on the equal adiabatic wall enthalpy and making it difficult to accurately simulate the real aerodynamic heating environment in the current test simulation method, and provides guarantee for heat transfer and ablation test research of thermal protection/insulation material under the high temperature aerodynamic heating environment. The test conditions are not affected by the value of the adiabatic wall enthalpy. According to the method, most test devices can simulate the aerodynamic heating environment with high enthalpy.