International Conference on Methods of Aerophysical Research, ICMAR 2008

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1 International Conference on Methods of Aerophysical Research, ICMAR 2008 MULTICOMPUTER DATA ACQUISITION AND CONTROL SYSTEM FOR AERODYNAMIC BLOWDOWN WIND TUNNELS V.M. Gilyov, V.I. Zapryagaev, А.S. Pevzner Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, , Novosibirsk, Russia V.V. Garkusha, V.V. Yakovlev Design Institute for Computer Engineering SB RAS, , Novosibirsk, Russia B.N. Pishchik State Novosibirsk University , Novosibirsk, Russia Introduction Present-day nearly all experimental researches in aerodynamic wind tunnels are conducted with automation systems of data collection and processing. In view of several functions treated by the automations systems, an approach is gaining ground. It is associated with partitioning of system by separate independent subsystems, which are united with telecommunications into unique information space. Such as a multicomputer distribution system is actually being designed in the ITAM of SB RAS for hyper- and supersonic blowdown wind tunnels. The work on the system design is done according to the following principles [1 4]: unification of subsystem of automated data acquisition on the level of hardware and program interface; possibility of operative tuning for various concrete conditions of experiment conduction; unification of all data to the unique information space by the systems of data bases of calibrations, models and experiment results; modularity of hardware, as software tools. Structure of multicomputer automation system of experimental research in wind tunnel The structure of automation system of aerophysical researches done in supersonic wind tunnel was elaborated considering the problems area solved by the system. During the elaboration of system the main attention was paid to the ease of its operating, serviceability and durability, thus the system clearly represents the subsystems, each of which is oriented to accomplish determined tasks [5]. The system designed consists of six subsystems (Fig. 1): 1) Subsystem of slow processes data collection. This subsystem allows configuration of equipment set required for every concrete experiment. The subsystem given uses typical multifunctional analog and digital boarders and multiplexers of Advantech, LCard, as well as micrometric multimeters НР-34970А. The subsystem is running ОС Windows ХР and exercise functions of upper system level AWS (Automated work station) of the researcher transmitting the data to the united data base. 2) Subsystem of fast processes. The subsystem is produced basing on the industrial computer with ОС Windows 2000/XP. The video-input board is installed in the computer for video signals V.M. Gilyov, V.I. Zapryagaev, A.S. Pevzner, V.V. Garkusha, V.V. Yakovlev and B.N. Pishchik,

2 Section I from video camera and the board from fast-acting ADC, which function on at a time in every experiment according the researcher request. 3) Operator automated working station. It is designed for visualization of current state of selected elements of wind tunnel, and for protection operation and blocking. The operator automated working station shows the mnemonic diagram of aerodynamic installation with all actuating mechanisms (latches, valves. etc), control elements (keys and buttons) and main transducers with dynamic indication of their condition.. 4) Subsystem of blockage system and tunnel parameters input. The subsystem is based on the multichannel modules of communication device with the object CPI and industrial controller ICOP 6070 running QNX real-time operation system. By the means of this subsystem the blockage signals and tunnel parameters are entered are input, uniting all existing algorithms of blockages and protections, visualization of the rightness of preparation of the system and condition of control elements and executive devices on the operator automated working station. а) b) c) d) e) f) Fig. 1. Structure scheme of multicomputer-based automation system of experimental researches in supersonic aerodynamic wind tunnel: a subsystem of data acquisition of slow processors (AWS of researcher); b subsystem of measuring of fast processes; c AWS of operator; d subsystem data acquisition of blocking signals and tunnel parameters input; e subsystem of pressure measurement; f subsystem of pressure control in the main tunnel channel. 5) Subsystem of pressure measurement. This subsystem is designed for data collection basing on multi-channel pressure-measuring device (MID-100), which allows performing high-accuracy and multipoint measurement of pressure using the digital multimeter НР-34970А. The pressure measuring devices MID controlled by the modules of input/output (MIO), the values measured are transmitted through the controller ICOP 6070 to the upper level of the system the first diagram. 2

3 International Conference on Methods of Aerophysical Research, ICMAR ) Subsystem of pressure control in the main tunnel channel. The subsystem of pressure control is produced basing on the industrial controller ICOP It is used to control and direct pressure in settling chamber of wind tunnel. The problem of pressure control in the main channel of the tunnel with the accuracy required is very important while performing aerophysical experiment. To solve this problem we analyzed the existing system of tuning of wind tunnel Т-313 brought into operation in 1967, which is hydromechanical regulating system. By now days it is out-dated, significantly used and requires long-term setting of standard conditions and it supporting during experiments, which results by excessive and involuntary air consumption. Structure of information system of experimental research Since 1998 the experimental data of our plants are stored centrally. We accumulated a wide data archive (there are data of more than thousand experiments) and the problem of ordering the protocols archive and easement of search of the information required became very actual and needed while preparing every experiment. The structure system selected provides for collection in one place of all experimental data, geometrical characteristics of the models, video information in order to store centrally and to transfer then to the future soft and hardware platform. The protocols archive suggested in this work has a generalized structure in comparison with several existing data bases (DB) of aerodynamic experiment, which allows storing in it the data of all experiments conducted. Archive of experimental data System of acquisition data of T-313 Users System of acquisition data of T-326 Transducers and data of calibrations Fig. 2. Structure of information system. The information system is elaborated as five interdependent data bases: - DB Archive of experimental data (InterBase(Windows), FireBird(Linux)); - DB Transducers and calibration (InterBase(Windows), FireBird(Linux)); - DB Data collection on Т-313 (InterBase(Windows)); - DB Data collection on Т-326 (InterBase(Windows)); - DB Control signals (is being elaborated). 3

4 Section I The DB accomplished Archive of experimental data allows accomplishing following functions: - selecting data from the DB by the plant name, Mach number, model, operator; - sorting data by the properties given; for example it is possible to sort all the data according to the date of experiment; - work with archive data in experiment mode (diagrams of dependence of values studied and/or distribution of pressure in determined point of time); - revision of information about model and video information obtained during the experiment. The data of experiments are recorded in DB from the data acquisition program after the finish of the experiment and become available to all registered net users having client application of DB. The majority of DB properties are formalized and connected with corresponding manuals allowing finding the information required. Find commands are done through the SQL-requires to the server. Using the DB, an experimenter can see the data in such a manner, as they are represented in data acquisition programs, to build the diagrams of dependence of values studied or/and of pressure distribution at the determined time moment. All possibilities of the data acquisition programs (except the acquisition itself) are done in the DB Experimental data. To prepare the configuration and experiments conduction the information about the transducers used is needed. The first level of DB Transducers and calibrations contains information about all preps used. The second level of the base contains calibrations of every probe. Using the DB Transducers and calibrations an experimenter can select the transducers corresponding to the requirements of a certain experiment. It is possible to select the calibrations in the diapason required in dependence of the experiment needs. Two local DB Data acquisition on Т-313 and Data acquisition on Т-326 allows building technological map of the experiment (it affords an opportunity to select and configure the equipment required). The elaborated DB Control signals will contain archive of technological information about plants conditions collected by the system of input of blockage signals and tunnel parameters. Results of the experiments As an example of usage the system of automated data acquisition on the supersonic wind tunnel Т-313 the Fig. 3 shows the distribution of pressures on the power-low (MACH=2). 4 Fig. 3. Pressures curves.

5 International Conference on Methods of Aerophysical Research, ICMAR 2008 The diagram shows the dependence of the pressure measured on the body of rotation from longitudinal pitch for three counts made in different time points. The change of pressure between different curves characterizes the process of pressure assignment in pneumo-channel during the experiment. The table represented shows the change of indications of pressure during the experiment. It is possible to see that the 2 d and the 3 rd counts correspond to the steady pressure in measurements pneumo-channels and can be accepted as valid. The Fig.4 shows the archive of experimental data of the wind tunnel Т-326 (jet module). The diagram represents distribution of pressure in dependence on radial position of the tube of total pressure. The measurements are done for the jet section placed at a distance of 30 mm from the outlet section of convergent nozzle which diameter is 30 mm. The curve from two Pitot tubes shifted in radial direction from 0 mm to 30 mm using the measuring traversing probe for measuring total pressure on the flow of supersonic under-expanded jet. The mode of traversing probe and the interval of counts taken are programmed before. As soon as the plant starts working at standard conditions the measuring of pressure profile is done automatically, in such a case every value represented is the result of averaging from some reports (not less than 10) in order to increase the measurement accuracy. The description and analyze of data results is represented in [9]. Fig. 4. Values of pressure during transition of traversing probe along the radius of supersonic under-expanded jet, exhausting from convergent nozzle. Conclusion In such a manner, this work represents the multicomputer-based automation system of aerophysical researches in blowdown wind tunnels. Creating such a system allows accomplishing fundamental modernization of measuring system during experimental researches. The partition of the automation system into separate independent subsystems allows making the usage of measuring means more effective and simplifying the system and its operation as well. Conducting high-accuracy measurements allows enhancing accuracy and validity of experimental data. This system is actually used for registration of flow parameters, for weight, drainage and other kinds of tests. The system was applied to register velocity spaces, flows visualization and etc. 5

6 Section I The present work was done with financial support from Russian Foundation for Basic Research (grants of RFBR , ). REFERENES 1. Gilyov V.M., Zapryagaev V.I., Zvegintsev V.I., Garkusha V.V., Pishchik B.N. Automation system for aerophysical experiments // Intern. Conf. on the Methods of Aerophys. Research: Proc., Pt. II. Novosibirsk, P Gilyov V.M., Zapryagaev V.I., Pevzner A.S., Garkusha V.V., Pishchik B.N., Surodin S.P., Fedorov A.I. Application of two-level system of experiment automatization in a supersonic blowdown wind tunnel // Intern. Conf. on the Methods of Aerophys. Research: Proc., Pt. IV. Novosibirsk, P Zapryagaev V.I., Gilyov V.M., Baturin A.A., Kavun I.N., Pevzner A.S. Improved automation system for aerophysical experiments at ITAM SB RAS // Models and Methods in Aerodynamics: Proc. of the Third International School-Seminar, Evpatoria, June 5 14, Moscow: MCNMO, P Gilyov V.M., Zapryagaev, V.I., Garkusha, V.V., Pishchik B.N. Distributed system of aerodynamic experiment automation // Computation technologies, V.9. P. II. Almaty Novosibirsk, P Tchirkashenko V.F., Yudintsev Y.N. Development of the method of measuring parameters of sonic bang in supersonic wind tunnels aerodynamic. Preprint ITAM SB RAS 6 83, Novosibirsk, p. 6. Gilyov V.M., Zapryagaev V.I., Pevzner A.S., Garkusha V.V., Pishchik B.N., Fedorov A.I. Upgrade of data acquisition for supersonic wind tunnel // Intern. Conf. on the Methods of Aerophys. Research: Proc., Pt. IV. Novosibirsk, P Gilyov V.M., Zapryagaev V.I., Pevzner А.S., Baturin А.А., Sobstel G.М., Garkusha V.V., Fedorov А.I., Yakovlev V.V. Automation of experimental researches in supersonic wind tunnel // Transaction of the XXI All Russian seminar on stream, detached and fluctuating flows, Novosibirsk, th of August Novosibirsk, P Gilyov V.M., Zapryagaev V.I., Pevzner А.S., Garkusha V.V., Yakovlev V.V. Automation of scientific experiment in supersonic wind tunnels // Matters of II All Russian science-practical conference (Biysk, 30 January 1 February 2008 г.) /Biysk V.M. Shukshin Ped. State University. Biysk: V.M. Shukshin BPSU, P Zapryagaev V.I., Kavun I.N., Kiselev N.P. Flow structure in the initial section of the supersonic underexpanded jet, exhausting from the nozzle with chevrons. ICMAR