Tham khảo tài liệu 'wind tunnels and experimental fluid dynamics research part 16', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 588 Wind Tunnelsand Experimental Fluid Dynamics Research Fig. 2. Sketch of a typical test performed at the SCIROCCO Plasma wind tunnel After that the test article is inserted in the plasma flow by means of an automatic robot which is named Model Support System MSS fixed to the base of the test chamber. The main physical parameters are monitored by means of a Data Acquisition System DAS . Advanced instrumentations are installed both inside and outside the test chamber. The plasma flow is then collected in the diffuser whose main task is to reduce the plasma speed from supersonic values to subsonic ones. The diffuser is made by a convergent-divergent horizontal nozzle with a long central part at uniform section and it is cooled by an external cooling system. At the end of diffuser the air flow encounters the heat exchanger which reduces the temperature of the air consistently with the thermal strength of the materials used for the vacuum system which is located afterwards. The vacuum system generates and keeps the vacuum conditions required by the test. All the components located between the arc heater and the heat exchanger identify the SCIROCCO Test Leg. A system named DeNOx system follows the vacuum system and its aim is to reduce the amount of nitrogen oxide produced in the Test Leg during the test. In order to reduce the thermal energy produced in the various components of the Test Leg a water cooling system is used. Two water cooling circuits are used with two different values of the water pressure. In both the water is demineralised for two reasons first to avoid the salt deposition along the exchange surfaces which may reduce the heat exchange coefficients and second to avoid problems related to the electric conductivity of non demineralised water. The high pressure circuit is used to cool critical component of the Test Leg where very high heat exchange coefficients are needed the other components are cooled by the low pressure circuit. Moreover cooling water
