An experimental setup for bridge deck large-amplitude vertical-torsional coupled free vibration in wind tunnel test, which belongs to the technical field of wind tunnel test apparatus. The experimental setup includes the rigid model, the rigid circular rods, the lightweight rigid circular sprockets, the chains, the linear tensile vertical springs, the bearings, the sliders, and the guides. For the new setup, large-amplitude vertical-torsional coupled free vibration of a rigid deck model that failed in conventional testing device can be adapted by the vertical deformation of the springs without any lateral tilt. As a result, the possible nonlinear mechanical stiffness due to the springs tilt in conventional testing device is excluded. In addition, owing to the low rolling friction and damping between the sprockets and the chains, the mechanical damping ratio of the system are quite low and stable for very large-amplitude vibrations.

An experimental setup for bridge deck large-amplitude vertical-torsional coupled free vibration in wind tunnel test, which belongs to the technical field of wind tunnel test apparatus. The experimental setup includes the rigid model, the rigid circular rods, the lightweight rigid circular sprockets, the chains, the linear tensile vertical springs, the bearings, the sliders, and the guides. For the new setup, large-amplitude vertical-torsional coupled free vibration of a rigid deck model that failed in conventional testing device can be adapted by the vertical deformation of the springs without any lateral tilt. As a result, the possible nonlinear mechanical stiffness due to the springs tilt in conventional testing device is excluded. In addition, owing to the low rolling friction and damping between the sprockets and the chains, the mechanical damping ratio of the system are quite low and stable for very large-amplitude vibrations.

A system for monitoring a model in a wind tunnel is provided. The system includes a plurality of sensors attached to a model in a wind tunnel. Each sensor of the plurality of sensors is configured to measure an attribute of the model. The system also includes a computing device in communication with the plurality of sensors. The computing device is programmed to receive a plurality of signals from the plurality of sensors, store a first threshold and a second threshold based on normalized alarm limits associated with at least one of the plurality of sensors, analyze the plurality of signals based, at least in part, on the first threshold and the second threshold, determine that a potentially negative condition is occurring based on the analysis, and alert a user to the potentially negative condition.

A system for monitoring a model in a wind tunnel is provided. The system includes a plurality of sensors attached to a model in a wind tunnel. Each sensor of the plurality of sensors is configured to measure an attribute of the model. The system also includes a computing device in communication with the plurality of sensors. The computing device is programmed to receive a plurality of signals from the plurality of sensors, store a first threshold and a second threshold based on normalized alarm limits associated with at least one of the plurality of sensors, analyze the plurality of signals based, at least in part, on the first threshold and the second threshold, determine that a potentially negative condition is occurring based on the analysis, and alert a user to the potentially negative condition.

An experimental setup for bridge deck large-amplitude vertical-torsional coupled free vibration in wind tunnel test, which belongs to the technical field of wind tunnel test apparatus. The experimental setup includes the rigid model, the rigid circular rods, the lightweight rigid circular sprockets, the chains, the linear tensile vertical springs, the bearings, the sliders, and the guides. For the new setup, large-amplitude vertical-torsional coupled free vibration of a rigid deck model that failed in conventional testing device can be adapted by the vertical deformation of the springs without any lateral tilt. As a result, the possible nonlinear mechanical stiffness due to the springs tilt in conventional testing device is excluded. In addition, owing to the low rolling friction and damping between the sprockets and the chains, the mechanical damping ratio of the system are quite low and stable for very large-amplitude vibrations.

A large-amplitude vertical-torsional coupled free vibration testing device for wind tunnel test. The large-amplitude vertical-torsional coupled free vibration device for wind tunnel test includes rigid deck model, lightweight rigid rods, lightweight rigid circular aluminium hubs, the first thin strings, linear tensile vertical springs, and the second lightweight strings. Large-amplitude vertical-torsional coupled free vibrations of rigid deck models can be realized by using this device, in which the springs vertically deform without any tilt. In the traditional free vibration device, the spring may obviously tilt, and the linear torsional stiffness cannot be ensured. The device can be conveniently installed and the initial angle of attack can be easily adjusted. The extreme low and stable mechanical damping ratio required for large-amplitude vibrations can be readily guaranteed, owing to the invocation of the negligible rolling friction between the thin strings and the hub.

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.

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.

A system reproduces aerodynamic boundary layer transition conditions in a wind tunnel test environment under ambient to cryogenic temperature conditions. The system includes a test component disposed in the test environment that defines an exterior surface. A trip dot is mounted on the test component and has a first state, in which a distal surface of the trip dot is at a first elevation relative to the exterior surface of the test component, and a second state, in which the distal surface of the trip dot is at a second elevation relative to the exterior surface of the test component. An actuator is operably coupled to the trip dot and configured to transition the trip dot between first and second states. A controller remotely causes the actuator to transition the trip dot between the first and second states.

A system reproduces aerodynamic boundary layer transition conditions in a wind tunnel test environment under ambient to cryogenic temperature conditions. The system includes a test component disposed in the test environment that defines an exterior surface. A trip dot is mounted on the test component and has a first state, in which a distal surface of the trip dot is at a first elevation relative to the exterior surface of the test component, and a second state, in which the distal surface of the trip dot is at a second elevation relative to the exterior surface of the test component. An actuator is operably coupled to the trip dot and configured to transition the trip dot between first and second states. A controller remotely causes the actuator to transition the trip dot between the first and second states.