Measurement of temperature field in moving fluids is connected with many difficulties. Usage of point temperature measurement methods, such as Constant Current Anemometry (CCA), is limited to frequencies up to 3 kHz. This frequency should be the limiting factor for using the CCA in fluid when fast change of temperature occurs. This shortcoming of CCA measurements should be overcome by using of optical methods such as Digital Holographic Interferometry (DHI). It is necessary to employ a special holographic setup with double sensitivity instead of the commonly used Mach-Zehnder type of holographic interferometer in order to obtain the parameters sufficient for the studied cases. This setup is not light efficient like the Mach-Zehnder type but has double sensitivity. The article also shows the method of synchronization and the method for phase averaging of the acquired data. The presented DHI is based on a modified Twymann-Green setup. and Obsahuje seznam literatury
This article deals with the measurement of temperature fields in 3D airflow using an infrared camera and the measuring net with measuring targets. This method is based on the visualization of temperature fields on an auxiliary material (paper targets) which is inserted into the non-isothermal airflows. In the article is the description of the new developed measuring equipment for visualization 3D airstreams by an infrared camera. Temperature fields are made visible by an air-heating ventilator, and consequently the temperature field is evaluated. The ventilator generates approximately a rotate-circle airstream in the axis of ventilator mouth outlet. The results are compared to the similar measurement the using the equipment for visualization a temperature field in 2D airflows by an infrared camera and the compact sheet of textile. This measuring method can be used in many various applications such as air-heating and air-conditioning. and Obsahuje seznam literatury