A method of testing and/or controlling the operation of an axial turbomachine through which passes a gas stream, includes the following actions: measurement of operating parameters of the turbomachine, said parameters including pressure in the gas stream at different axial positions, and calculation of operating conditions of the turbomachine from the measured parameters and the Laplace coefficient of the gas passing through the turbomachine, wherein the measurement of parameters includes a measurement of the temperature of the gas stream, and the calculation of operating conditions includes a determination of the Laplace coefficient on the basis of the measurement of the temperature of the gas stream.

Methods and apparatus for monitoring fluid-dynamic drag on an object, such as a bicycle, ground vehicle, watercraft, aircraft, or portion of a wind turbine are provided. An array of sensors obtain sensor readings for example indicating: power input for propelling the object; air speed and direction relative to motion of the object; and ground speed of the object. Sensor readings may also indicate: temperature; elevation and humidity for providing a measurement of air density. Sensor readings may also indicate inclination angle and forward acceleration. Processing circuitry determines a coefficient of drag area based on the sensor readings and optionally one or more stored parameters, according to a predetermined relationship. A pitot tube based apparatus for measuring fluid speed and direction is also provided. Methods for dynamic in situ calibration of the pitot tube apparatus, and of adjusting correction factors applied to correct measurement errors of this apparatus are also provided.

The present invention discloses a pollutant generation system. The pollutant generation system includes a pollution source and a pollutant emitter. The pollutant emitter is connected to the pollution source. The pollution source is composed of two gases including air and methane. The flows of the gases are strictly controlled. Then, the gases enter a magnetic bead glass bottle. Due to the disturbance of magnetic beads to the flowing of the gases, the gases are sufficiently disordered, and the two gases are sufficiently mixed by using a spiral tube to generate a uniform and stable pollution source.

A wake generator for placement in a wind tunnel between a wind source and a test object includes a first frame member having a first track formed thereon, where the first track has a shape including a first side that is substantially rounded and a second side that is substantially flat. The wake generator may include a mounting plate disposed within a perimeter of the first track, where the mounting plate is rotatable relative to the first frame member about a first axis. The wake generator may also include a plurality of bars slidably engaged to the mounting plate and structurally configured to traverse along the first track when the mounting plate is rotated about the first axis, where each of the plurality of bars includes a pivotal connection allowing each of the plurality of bars to pivot about the pivotal connection when traversing along the first track.

A dynamic five-hole probe includes a pressure sensing part, a pressure measuring hole transition section, a pressure acquisition section, dynamic pressure sensors and flexible wall pressure buffering tubes, the pressure sensing part being provided with pressure measuring holes to sense three dimensional dynamic pressure components of an airflow; the pressure measuring hole transition section transits from an inlet end surface five-hole structure into an outlet end surface five-hole structure; the pressure acquisition section has therein a centrally symmetric pressure measuring hole structure; pressure sensor mounting holes are in communication with the five pressure measuring holes; each of the dynamic pressure sensors is mounted in a corresponding one of the sensor mounting holes to measure a dynamic pressure of the airflow. The pressure sensing part may have a diameter of 3 mm or less.

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.

An electrode performance evaluation system and an electrode performance evaluation method is disclosed. The method includes acquiring impedance measurement data for different frequencies by applying an alternating current signal to an electrode assembly including an electrode which is immersed in an electrolyte solution, calculating impedance calculation data for different frequencies while changing the frequency of an impedance equation corresponding to a circuit model of the electrode assembly, calculating the resistance value of ion bulk resistance in the electrolyte solution using the ion conductivity of the electrolyte solution, the area of the electrode and the thickness and porosity of an active material layer of the electrode, and determining effective tortuosity as a factor of the electrode performance based on the impedance measurement data for different frequencies, the impedance calculation data for different frequencies and the resistance value of the ion bulk resistance.

Provided is a method for determining at least one characteristic of a boundary layer a wind turbine rotor blade, including capturing at least one movement of at least one flexible element of at least one sensor being attached to or being part of a surface of the rotor blade, determining the at least one characteristic of the boundary layer based on the at least one captured movement of the at least one flexible element. Further, a sensor device, a wind turbine and a device as well as a computer program product and a computer readable medium are suggested for performing the method.

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 wake generator for placement in a wind tunnel between a wind source and a test object includes a first frame member having a first track formed thereon, where the first track has a shape including a first side that is substantially rounded and a second side that is substantially flat. The wake generator may include a mounting plate disposed within a perimeter of the first track, where the mounting plate is rotatable relative to the first frame member about a first axis. The wake generator may allow for better simulation of unsteady turbine wakes that influence cooling flow. The wake generator may also include a plurality of bars slidably engaged to the mounting plate and structurally configured to traverse along the first track when the mounting plate is rotated about the first axis.