The present disclosure provides a large-scale low-temperature controllable atmospheric boundary layer test system and method for wind and snow simulation. The system includes an atmospheric boundary layer wind tunnel, a plenum chamber and a refrigeration system. The atmospheric boundary layer wind tunnel includes an upper flow channel and a lower flow channel communicating with each other end to end. A power section is arranged in the upper flow channel. A settling chamber, a contraction section and a test section are sequentially arranged in the lower flow channel. Corners of a closed return wind tunnel are respectively provided with a transition section. A fan is disposed in the power section. An air heat exchanger is disposed in the settling chamber. The plenum chamber is divided by a partition into a storage room for storing snow particles and an operation room provided with a snow particle vibratory spreading device. The storage room is located at an upper part of the settling chamber. An air cooler is disposed in the storage room. The operation room is located at an upper part of the test section. The snow particle vibratory spreading device spreads snow particles that uniformly fall into the test section. The refrigeration system outputs a secondary refrigerant for heat exchange for the air cooler in the plenum chamber and the air heat exchanger in the atmospheric boundary layer wind tunnel. According to the present disclosure, the natural snowfall process is simulated through the cooperation of various parts of the system.

The present disclosure provides a large-scale low-temperature controllable atmospheric boundary layer test system and method for wind and snow simulation. The system includes an atmospheric boundary layer wind tunnel, a plenum chamber and a refrigeration system. The atmospheric boundary layer wind tunnel includes an upper flow channel and a lower flow channel communicating with each other end to end. A power section is arranged in the upper flow channel. A settling chamber, a contraction section and a test section are sequentially arranged in the lower flow channel. Corners of a closed return wind tunnel are respectively provided with a transition section. A fan is disposed in the power section. An air heat exchanger is disposed in the settling chamber. The plenum chamber is divided by a partition into a storage room for storing snow particles and an operation room provided with a snow particle vibratory spreading device. The storage room is located at an upper part of the settling chamber. An air cooler is disposed in the storage room. The operation room is located at an upper part of the test section. The snow particle vibratory spreading device spreads snow particles that uniformly fall into the test section. The refrigeration system outputs a secondary refrigerant for heat exchange for the air cooler in the plenum chamber and the air heat exchanger in the atmospheric boundary layer wind tunnel. According to the present disclosure, the natural snowfall process is simulated through the cooperation of various parts of the system.

A vortex vibration wind tunnel test model system for a long-span bridge and a test method thereof is disclosed. In the test model system, the base is provided with a plurality of adjustment members, each of the adjustment members is provided with a cantilever rod, and all of the cantilever rods are cantilevered in the same direction; a beam body model is provided on a cantilevered end of all of the cantilever rods; a displacement measuring member is provided below the cantilever rod, and the horizontal distance between the displacement measuring member and the beam body model exceeds 2 times a width value of the beam body model, the displacement measuring member being away from the surface of the beam body model and the position of directly below the beam body model. Therefore, the state response data of the position of the cantilever rod can be collected in real time. By calculating the state response data of the cantilever end of the cantilever beam, the state response data of the beam body model is obtained, which effectively reduces the damping of the model system and improves the accuracy of the model technical parameters. The test method is simple and reliable, which improves the real reliability of the wind tunnel test data, and can effectively meet the requirements of the high-order vortex vibration wind tunnel test for the long-span bridge.

A vortex vibration wind tunnel test model system for a long-span bridge and a test method thereof is disclosed. In the test model system, the base is provided with a plurality of adjustment members, each of the adjustment members is provided with a cantilever rod, and all of the cantilever rods are cantilevered in the same direction; a beam body model is provided on a cantilevered end of all of the cantilever rods; a displacement measuring member is provided below the cantilever rod, and the horizontal distance between the displacement measuring member and the beam body model exceeds 2 times a width value of the beam body model, the displacement measuring member being away from the surface of the beam body model and the position of directly below the beam body model. Therefore, the state response data of the position of the cantilever rod can be collected in real time. By calculating the state response data of the cantilever end of the cantilever beam, the state response data of the beam body model is obtained, which effectively reduces the damping of the model system and improves the accuracy of the model technical parameters. The test method is simple and reliable, which improves the real reliability of the wind tunnel test data, and can effectively meet the requirements of the high-order vortex vibration wind tunnel test for the long-span bridge.

A chassis dynamometer for motorcycles with a combustion engine, having a mounting unit, at least one fastening unit, an operating unit, a control unit and a roller for recording the peripheral speed of a motorcycle rear wheel is disclosed. The chassis dynamometer has a flow unit a drive unit, a diffuser and an outflow unit arranged downstream of the diffuser in the direction of flow where the diffuser and outflow unit form a flow channel carrying gas in the operating state, wherein the diffuser can be driven by the drive unit, where the control unit controls the drive unit as a function of the peripheral speed of the roller in such a way that a speed of the gas emerging from the outflow unit in the operating state is substantially equal to the peripheral speed at least from a peripheral speed of 150 km/h.

A cooling system for a wind tunnel is disclosed. The heat exchanger of the present disclosure is formed as a turning vane in an airflow duct of a re-circulating wind tunnels. The individual vanes are formed from extruded aluminum with coolant fluid channels running continually down the length of the vane. One or more channels can be used, depending on the application of vane and the cooling capacity needed. The exterior of the vanes are formed in an airfoil shape to efficiently turn the air flow the desired amount in a manner well known in the art. The turning vanes are connected to a fluid supply with single piece connectors that removably attach to the turning vanes. In the depicted embodiment the connectors are attached with screws. In the depicted embodiment the connectors are formed as a single piece in a two-piece injection mold.

A cooling system for a wind tunnel is disclosed. The heat exchanger of the present disclosure is formed as a turning vane in an airflow duct of a re-circulating wind tunnels. The individual vanes are formed from extruded aluminum with coolant fluid channels running continually down the length of the vane. One or more channels can be used, depending on the application of vane and the cooling capacity needed. The exterior of the vanes are formed in an airfoil shape to efficiently turn the air flow the desired amount in a manner well known in the art. The turning vanes are connected to a fluid supply with single piece connectors that removably attach to the turning vanes. In the depicted embodiment the connectors are attached with screws. In the depicted embodiment the connectors are formed as a single piece in a two-piece injection mold.

The invention provides a method for computational fluid dynamics and apparatuses making enable an efficient implementation and use of an enhanced jet-effect, either the Coanda-jet-effect, the hydrophobic jet-effect, or the waving-jet-effect, triggered by specifically shaped corpuses and tunnels. The method is based on the approaches of the kinetic theory of matter, thermodynamics, and continuum mechanics, providing generalized equations of fluid motion. The method is applicable for slow-flowing as well as fast-flowing real compressible-extendable fluids and enables optimal design of convergent-divergent nozzles, providing for the most efficient jet-thrust. The method can be applied to airfoil shape optimization for bodies flying separately and in a multi-stage cascaded sequence. The method enables apparatuses for electricity harvesting from the fluid heat-energy, providing a positive net-efficiency. The method enables efficient water-harvesting from air. The method enables generators for practical-expedient power harvesting using constructive interference of waves due to the waving jet-effect.

A portable aeroacoustic wind tunnel includes a modular building structure. The wind tunnel is assembled together on-site at an assembly plant outdoors and on the ground and disassembled into sub-assemblies for transportation. A separate control building includes fan controls, acoustic measurement controls and windows for visual observation. A portable generator provides power to the wind tunnel that is equipped with acoustic dampening features. The modular building structure and control building can be shipped in a cost-effective manner.

A portable aeroacoustic wind tunnel includes a modular building structure. The wind tunnel is assembled together on-site at an assembly plant outdoors and on the ground and disassembled into sub-assemblies for transportation. A separate control building includes fan controls, acoustic measurement controls and windows for visual observation. A portable generator provides power to the wind tunnel that is equipped with acoustic dampening features. The modular building structure and control building can be shipped in a cost-effective manner.