Material Processing Using Supersonic Heterogeneous Jet Flow
The Material Processing with the Two-Phase Jet Flow. (The Study of the Supersonic Two-Phase Jet Flow with the Aim to Intensify the Material Processing)
Tech Area / Field
- MAT-SYN/Materials Synthesis and Processing/Materials
- PHY-NGD/Fluid Mechanics and Gas Dynamics/Physics
8 Project completed
Senior Project Manager
Latynin K V
Central Research Institute of Machine Building (TsNIIMash), Russia, Moscow reg., Korolev
- Vavilov State Optical Institute (GOI) / Small-Scale State Enterprise "Laser Physics", Russia, St Petersburg\nLimited Liability Enterprise "Complex Erosion Technologies RAS", Russia, Moscow
- Akros, France, Chambery\nGerLoSoft, Germany, Wuppertal\nUniversita Degli Studi di Roma "Tor Vergata" / Department of Mechanical Engineering, Italy, Rome\nvon Karman Institute for Fluid Dynamics, Belgium, Rhode Saint Genèse
Project summaryThe main objective of the project is to widen and to generalize the experience in studies of the single-, group- and jet action of high-speed particles on the material being processed, and also to develop the unified model of the gasdynamic path for their accelerating; such model should be applicable for providing the optimal conditions of the heterogeneous flow action on the material surface being processed.
Among different methods and means for the material processing, the use of supersonic heterogeneous flows and systems for their initiation is, in many cases, optimal.
The main result of the accumulated experience in the study of the material erosion resistance is the following: the presence of even the small number of particles in the flow past the body causes the substantial increase in the value of the convective heat flux to the surface, as well as the substantial increase in the value of the material linear ablation rate. On the basis of these data it has been proposed to use the supersonic heterogeneous jet with the aim to develop the conversion technologies (for example, the technology of cutting the materials and constructions in the civil engineering.
The technique for the material processing with the two-phase jet flow in principle differs from the existing techniques for the material processing. The mechanism of high-speed particle action on the work material is the microshock-wave one. Multiple repetitions of impacts, like to the low-cycle fatigue, substantially decrease the material resistance near the surface and does not cause the cracking of the whole material when its processing.
The designing, the calculating and the experimental try-out of the gasdynamic path for the acceleration of particles is one of the most intricate problems in the gas dynamics, the calculus mathematics and the experimental technology. Till recently this problem for concrete applications in civil industries was solved, mainly, empirically. Such approach is unproductive, because it requires a great number of expensive experiments and cannot provide the needed parameters of the heterogeneous flow. For different technical applications (the cold/hot powder spraying, the ground-test modeling of the supersonic flight through the atmosphere with natural and artificial formations, and so on) the gasdynamic paths for the acceleration of particles are applied. Such paths often are not optimized with respect to the governing parameters. In the most of such tasks the maximal possible velocity of particles impact with the streamlined surface is required (the supersonic velocity is desired). Hence, it is appropriate to have such the unified model of the gasdynamic path for the acceleration of particles, which would make possible to provide the high efficiency of the acting upon the surface being processed.
Principles of the designing the gasdynamic path constructions combining the universal and the optimal properties (power, weight, technological, ecological, etc.) are unknown at present.
It is anticipated that the scientific foundations for creating the gasdynamic path of the supersonic heterogeneous facility intended to intensify the material processing would be developed within the framework of the project.
The expected results of the project execution are as follows:
- The mathematical model of the supersonic nozzle capable to provide the maximal velocity of particles at its outlet section;
- The mathematical model of the gasdynamic path providing the choice of such relation between potential parameters of the gas in the facility prechamber (the total pressure and the stagnation temperature) and the mass-overall parameters of particles capable to provide the maximal particle kinetic energy flux to the surface being processed;
- The engineering technique for calculating the wall position behind the nozzle outlet section, the application of which would make possible to provide the minimal particle deceleration in the shock layer in front of the streamlined wall and in the cavity that forms as a result of the material processing;
- The laboratory facility for creating the hypersonic two-phase flow;
- Methods and means for studying the two-phase flow parameters by means of the holographic and the laser disdrometers using the sweep technique;
- The technique for estimating the efficiency of the particle acceleration depending on the gas parameters in the facility prechamber.
Results may be used in the construction- and other civil branches of industry when creating the supersonic gasdynamic heterogeneous facilities for the material processing. The delivery of results to other research/design institutions is also possible. The practical application of the project results will make possible to rise the operation efficiency of such facilities, and also to reduce the cost of development of their gasdynamic units.
The commercial value of the project is defined by the possibility of the further developing the competitive equipment for the material processing that could be used in many branches of industry.
The project activity provides the reorientation of the work direction of the project participants to peaceful purposes.
Scientists in many countries investigate the problem of the material processing optimization. So works on the project are supposed to be executed with the foreign collaborators.
The technical approach to the project execution supposes the performing of the complex of experimental and calculation-theoretical works. During the project activity the methods for the physical and mathematical modeling the processes of the particle acceleration in the nozzle supersonic part and the particle deceleration in the shock layer within the area of the material processing.
The research and development works on the creation of the laboratory stand for the material processing with the supersonic heterogeneous flow, and also calculations of optimal processing regimes from the viewpoint of obtaining the maximal values of the particle kinetic energy flux on the surface being processed, will be performed.
The development and the application of the photographic technique of the particle flow image sweep, the laser disdrometer and means for the holographic disdrometry will also be a new step in experimental researches of supersonic heterogeneous units. The application of such units will makes possible to determine the particle parameters at the supersonic nozzle outlet section, as well in the shock layer in front of the surface of the material being processed.
As a result of the project, 9 annotated reports, 2 annular scientific and technical reports, and also 1 final report will be delivered. Results of the project activity are supposed to be discussed at the presentation. Besides, 3 scientific and technical papers will be prepared for publishing.
The role of foreign collaborators consists in the specification of technical requirements to supersonic heterogeneous units for the material processing, being developed, under different conditions of their application. The foreign collaborators would help to establish contacts of the project participants with the foreign firms and scientists interested in results of the project researches.
In the project participating institutions (FSUE “TsNIIMash” and LLE “CET RAS”) the methodology approaches have been created those make possible to develop methods for optimizing the particle acceleration in the supersonic nozzles and for minimizing the particle deceleration in the shock layer in front of the streamlined wall and in the cavity formed in the material as a result of its processing.
Results of the analysis of studies obtained in FSUE “TsNIIMash” and LLE “CET RAS” indicated that at their basis it is possible to develop the unified model of the gasdynamic path for the particle acceleration. Such model could be used for providing the maximal results of the particle action upon the streamlined wall as applied to different technology problems and, in particular, for processing the materials with the two-phase flow.
In this connection, the methods of the holographic and the laser disdrometry developed earlier within the framework of the ISTC project # 474-98 in FSUE “TsNIIMash” together with some specialists from the SSSE “Laser Physics” (the methods permit to measure the particle distribution and sizes in the flow) and the methods of the multipulse holographic velocimetry (such methods permit to obtain an information about particle velocities) are of great importance. This gives a unique possibility to control the process of forming the heterogeneous flow and its action upon the material being processed.
As a result of the project execution, the scientific and methodology foundations for the material processing with the supersonic heterogeneous flow and the mathematical model of the gasdynamic path for optimizing the particle acceleration providing the maximal possible power action of the particle flow upon the surface being processed will be created.