Department of material desintegration
Staff -
Research topics -
Scientific achievements -
Technical equipment
Projects solved in recent years -
Selected publications
Personnel
- Josef Foldyna, Ph.D.
head of the department
- Libor Sitek, Ph.D.
deputy head of the department
- Zdenek Riha, Ph.D.
- Jiri Klich, M.Sc.
- Ass. Prof. Jan Valicek, Ph.D.
- Petr Hlavacek, M.Sc.
- Daria Novakova
- Ludek Pivoda
- Prof. Jaroslav Vasek, Dr.Sc.
emeritus scientist
- Michal Zelenak, M.Sc.
Main research topics
The research activities of the department are aimed in particular at the disintegration
of rocks and geomaterials by a high speed water jet. Problems related to rock cutting
by mechanical tools, the determination of workability and abrasiveness of rocks are
also studied.
-
Intensification of high-speed water jets and their effects
Research activities are directed at the study of the dynamic behaviour of a pulsating
water flow, the definition of excitation and propagation processes of high-frequency,
high pressure pulsations in the liquid and their utilization in generating pulsating,
high-speed liquid jets. The objective of the research is to understand the fundamental
processes of generation and transmission of pulsations in the high-pressure system
along with the formation of the pulsating jet and its interaction with the material.
-
Abrasive materials for abrasive water jet
This topic covers research carried out in the area of new abrasive materials (both
natural and artificial). The research is aimed at defining the crucial properties of
abrasive materials from the point of view of both maximizing the cutting performance
and minimizing the wear on the cutting head. The negative impacts of these materials
on the working and living environment is also studied. The objective of the research
is to develop a new generation of abrasive materials.
-
Numerical simulation of flow
Compressible liquid flow in the nozzle used in high-speed water jet technology
represents the main application of numerical simulation in the department.
Mathematical models are created using ANSYS software. Models allow the study of
liquid behaviour in the tube and downstream at the nozzle exit. Subsequently, the
whole solved assembly is optimized to obtain the best efficiency from the simulated
system. Modifications are verified by laboratory experiments. Knowledge and skills
obtained while using ANSYS software are also utilized for solving problems of liquid
flow and stress analysis in cooperation with industry.
-
Study of topography and quality of surfaces
This area studies the influence of technological parameters on the topography of
a machined surface for different types of materials. It also finds links between
force action, vibration, working pressure fluctuation, acoustic emission and
topography of the machined surface. Analysis is carried out by applying new layers
to on the machined surface.
-
New areas of high-speed water jet utilization
This research is oriented primarily around using the abrasive water jet in different
machining techniques (turning, milling, polishing, drilling, etc.) in
difficult-to-machine and non-machinable materials, such as composites, ceramics,
high-strength alloys, glass, rocks, etc. It also studies the the utilization of
high-speed water jets for ultra-fine grinding and disintegration of materials
(primarily geomaterials) to produce submicron particles.
Important scientific achievements
- The generation of a pulsating water jet for the disintegration of material
The result concerns the use of high pressure water jets for cutting and generally
disintegrating materials. The generation of sufficiently high pressure pulsations
in water upstream of the nozzle exit enables the creation of a pulsating liquid jet
that emerges from the nozzle as a continuous stream which forms pulses at certain
standoff distances from the nozzle exit. The advantage of such a pulsating jet over
a continuous one is based on the fact that the initial impact of pulses on the target
surface generates cyclically and an impact pressure that is several times higher than
the stagnation pressure generated by the action of continuous jet under the same
working conditions. In addition, the action of a pulsating jet also induces both
fatigue and shear stresses in the target material due to the cyclic loading of the
target surface and the radial high speed flow across the surface. This further
improves the efficiency of the pulsating liquid jet in comparison with the continuous
flow. An original method of generating a pulsating liquid jet was recently developed
and extensively tested. The method is based on the generation of acoustic waves by
an acoustic actuator on the pressurised liquid and their transmission via a
pressurised system to the nozzle. Research into the fundamentals of the excitation
process and the propagation of acoustic waves (and/or high-frequency pressure
pulsations) in liquid via a high-pressure system and their influence on the formation
and properties of a pulsating liquid jet was crowned by the granting of a Czech
patent and the completion of a license agreement for the manufacture of one piece
of an acoustic generator of pressurised pulsations. At present, the cooperative
agreement with an industrial partner which will lead to the signing of an exclusive
licence agreement for the manufacture, use and sale of generators based on the above
mentioned patent is being prepared.
The achievement was included in most important results of basic and targeted research
of the Academy of Sciences in 2008 (see
Annual Report of the Academy of Sciences of the Czech Republic in 2008
, in czech).
- Removal of degraded surface layers of concrete by high-speed water jets
Laboratory experiments concerned with the removal of degraded surface layers of
concrete by high-speed continuous and pulsating water jets, were prepared in
cooperation with Brno University of Technology, Faculty of Civil Engineering and
VSB - Technical University of Ostrava, Institute of Physics. Concrete blocks of
precisely-defined properties were created; some of them were stored or tested by
cyclic loading in different corrosive environments (freezing effect, the effect of
chemical de-freezing agents, long-term effects of chlorides, sulphates and nitrates).
Several testing samples were left as reference samples, i.e. not exposed to any
corrosive environment. The pulsating jet achieved a higher efficiency in all cases
compared to a continuous jet under the same working conditions. However, the ratio
of volume removed from the concrete test sample by both pulsating and continuous
jets varied considerably according to type and degree of sample degradation and
the cutting parameters. While continuous jets removed only the upper part of the
cement paste, pulsating jets penetrated deeper and removed cement paste to aggregates
at given testing conditions. Thus, pulsating jets are able to remove selectively
degraded concrete layer and preserve “healthy concrete“ following the application
of repair coatings and mortars also at low water pressures. A higher roughness of
the concrete substrate treated by pulsating jets leads to better adhesion of newly
applied layers.
- Numerical models of high pressure systems with an acoustic actuator
Numerical models of high pressure systems with an integrated acoustic actuator of
high pressure pulsations were created. They allowed for the theoretical study of
the processes of excitation and propagation of pressurised pulsations. Results of
numerical simulation of pressurised pulsations demonstrate that relatively
complicated geometries with one or two L-bows or relatively long liquid waveguide
allow propagation of pressure pulsations from source to nozzle. The intensity of
pulsations upstream from the nozzle exit can be substantially affected by defining
the dimensions of separate parts of the high-pressure system and its tuning to
resonance.
- Visualization of the pulsating jet
A special method of visualization of pulsating water jets based on the application of
stroboscopic effect was elaborated. The frequency of stroboscope flashing is controlled
by the frequency of the pressure pulsations in the high-pressure system which generates the
pulsating jet. The visualization is used to study the influence of operating parameters and
the geometric configuration of the acoustic generator of pressure pulsations on the formation
and the morphology of the pulsating water jets.
- Abrasives for high-speed water jet technologies
Abrasive materials were evaluated from both mineralogical and petrological points
of view. Their behaviour during the process of abrasive water jet generation and
its action on the material to be cut was also looked at. Methodologies for the
assessment of the initial properties of abrasive concentrates, their cutting
efficiency in reference materials and the wearing effects on the focusing tube
were developed. This was together with a methodology for description and morphological
analysis of grains and cutting kerfs in macro- and micro-scales by image analysis.
The determination of biological noxiousness of the respirable dust fraction, which
results from the disintegration of natural and synthetic abrasives and minerals of
the quartz group during application of abrasive water jet,represents another original
result of the research. The work contributed to the formulation of both enduring
problems and new themes for further research in the above mentioned area.
Technical equipment
-
High pressure pump based on unit Hammelmann equipped with intensifier Flow (maximum
operating pressure 380 MPa, max. flow rate up to 3.5 liters per minute) including
accessories (filtration unit, high-pressure tubes, etc.)
-
High pressure pump PTV 37-60 (one intensifier, maximum operating pressure 415 MPa,
maximum flow rate up to 3.68 liters per minute) including accessories
-
High-pressure plunger pump KUNZ Hranice (maximum operating pressure 120 MPa, max. flow
rate up to 45 liters per minute)
-
X-Y cutting system Nessap 1000-V specially designed for water jet and abrasive water
jet cutting
-
X-Y CNC cutting system WJ2020-1Z-D-PJ 2000 x 2000 mm with swing diamond cutting head
specially designed for water jet and abrasive water jet cutting
-
Three-component dynamometer Kistler with charge amplifier
-
Four highly sensitive piezoelectric pressure sensors Kistler with charge amplifiers
-
Patented sensor for measurement of the jet stagnation force (patent No. PV 7884-1988)
-
Acoustic generator of pulsating jet 20 kHz
-
Acoustic generator of pulsating jet 40 kHz
-
Stroboscopic device for visualization of pulsating jet
-
Measuring station based on notebook equipped with multifunction DAQ device National
Instruments (16-bit) and LabVIEW Full Development System software
-
Device for measurement of rock abrasiveness according to standard ON 44 1121
-
Laser Particle Sizer analysette 22 NanoTec wet - Fritsch
-
Workstation FSC CELSIUS R650: 2 processors Quad-Core Xeon X5460 3.16 GHz,
RAM 32 GB, HDD 2x 500 GB
-
CFD software ANSYS for simulation and modelling of high speed fluid jet
Projects solved in last years
- International project CNR Italy – AV CR Cutting and disintegration of hard rocks with water jet assistance. Special instruments, approaches and evaluation of cutting and disintegration performance (2004-2006), CSGM CNR, Cagliari, Italy.
- International project CNR Italy – AV CR Rock cutting with assistance of high-energy water jet. Preparation of special methods of measurement and evaluation of cutting performance (2001-2003), CSGM CNR, Cagliari, Italy.
- Project of bilateral cooperation between AVCR and PAN Poland: Application of advanced research methods to description of rocks and their discontinuities (Instytut Mechaniky Gorotworu PAN Krakow, Poland, 2006-2008).
- International project of Czecho-Slovak scientific and technical cooperation in the frame of program Kontakt No. 169 Development of ultrasonic generator based on piezoelectric transducer for modulation of high-speed water jet (2004-2005), Ecoson s.r.o. Nove Mesto nad Vahom, Slovakia.
- International project of Czecho-Slovak scientific and technical cooperation in the frame of program Kontakt No. 206 Development of ultrasonic nozzle based on hydrodynamic generator for generation of modulated high-speed water jets (2002-2003), Ecoson s.r.o. Nove Mesto nad Vahom, Slovakia.
- Grant project GA CR No. 105/03/0183 Development of novel technique for quarrying and cutting of ornamental stones, evaluated as excellent.
- Grant project GA AVCR No. 1QS300860501 Novel technique for cleaning and removal of surface layers and repair of concrete structures, evaluated as excellent.
- Grant project GA CR No. 105/00/0235 Forced modulation of water jet by ultrasonic, evaluated as excellent.
- Grant project GA AVCR No. A2086001 Hydrodynamic generator of pulsed jets.
- International project INCO Copernicus No. IC 15 CT98 0821 Abrasive water jet cutting, a clean technology. (9 partners from Germany, Italy, Poland, Hungary, Romania, Slovenia, 1999-2002).
Selected publications
- Foldyna, J., Heiniger, K. Mettler, S., Sitek, L., Scucka, J. Enhancing of Water Jet Effects by Pulsations. Manufacturing Engineering 4/2007,. pp. 30-33, ISSN 1335-7972.
- Nowakowski, A., Młynarczuk, M., Sitek, L., Foldyna, J. Wytrzymałość skały na rozciąganie – porownanie wynikow testu bezpośredniego rozciągania i testu brazylijskiego (Tensile strength of rock – comparison of results of direct tension test and Brazilian test). Sbornik vedeckych praci VSB-TU c. 2, roc. IX, rada stavebni, VSB-TU 2009, pp. 201 – 217, ISBN 978-80-248-2119-1, ISSN 1213-1962.
- Foldyna, J. Sitek, L. Scucka, J. Martinec, P. Valicek, J. Palenikova, K. Effects of pulsating water jet impact on aluminium surface. Journal of material processing technology Vol. 209, Iss. 20 (2009), pp. 6174–6180. Elsevier, 2009. ISSN 0924-0136.
- Bortolussi, A., Foldyna, J., Ciccu, R., Scucka, J., Martinec, P., Sitek, L. Ornamental stone surface treatment by pulsating water jets. 9th Pacific Rim Int. Conf. on Water Jetting Technology, 20. - 23. 11. 2009, Koriyama, Japonsko, IAP,Ltd. 2009, pp. 189-193, ISBN 4-902590-14-8.
- Sitek, L., Foldyna, J., Scucka, J., Martinec, P., Bodnarova, L., Hela, R. Utilization of Potential of Pulsating Jets for Removal of Concrete Layers. 9th Pacific Rim Int. Conf. on Water Jetting Technology, 20. - 23. 11. 2009, Koriyama, Japonsko, IAP,Ltd. 2009, pp. 181-187, ISBN 4-902590-14-8.
- Scucka, J., Foldyna, J., Sitek, L., Martinec, P., Valicek. J. Testing of fan jet nozzles for pulsating jets generation. 9th Pacific Rim Int. Conf. on Water Jetting Technology, 20. - 23. 11. 2009, Koriyama, Japonsko, IAP, Ltd. 2009, pp. 195-200, ISBN 4-902590-14-8.
- Foldyna, J. Research and development of pulsating water jets. In Pacific Rim International Conference on Water Jetting Technology /9./ Proceedings. Koriyama: Water Jet Technology Society of Japan, 2009. S. 171-179. ISBN 4-902590-14-8.
- Hlavacek, P., Valicek, J., Hloch, S., Gregr, M., Foldyna, J., Kozak, D., Sitek, L., Kusnerova, M., Zelenak, M. Measurement of Fine Grain Copper Surface Texture Created by Abrasive Water Jet Cutting. Strojarstvo 51(4), 2009, 273-279, ISSN 0562-1887.
Projects solved in recent years - Selected publications
Personnel
|
|
Main research topics
The research activities of the department are aimed in particular at the disintegration of rocks and geomaterials by a high speed water jet. Problems related to rock cutting by mechanical tools, the determination of workability and abrasiveness of rocks are also studied.
-
Intensification of high-speed water jets and their effects
Research activities are directed at the study of the dynamic behaviour of a pulsating water flow, the definition of excitation and propagation processes of high-frequency, high pressure pulsations in the liquid and their utilization in generating pulsating, high-speed liquid jets. The objective of the research is to understand the fundamental processes of generation and transmission of pulsations in the high-pressure system along with the formation of the pulsating jet and its interaction with the material.
-
Abrasive materials for abrasive water jet
This topic covers research carried out in the area of new abrasive materials (both natural and artificial). The research is aimed at defining the crucial properties of abrasive materials from the point of view of both maximizing the cutting performance and minimizing the wear on the cutting head. The negative impacts of these materials on the working and living environment is also studied. The objective of the research is to develop a new generation of abrasive materials.
-
Numerical simulation of flow
Compressible liquid flow in the nozzle used in high-speed water jet technology represents the main application of numerical simulation in the department. Mathematical models are created using ANSYS software. Models allow the study of liquid behaviour in the tube and downstream at the nozzle exit. Subsequently, the whole solved assembly is optimized to obtain the best efficiency from the simulated system. Modifications are verified by laboratory experiments. Knowledge and skills obtained while using ANSYS software are also utilized for solving problems of liquid flow and stress analysis in cooperation with industry.
-
Study of topography and quality of surfaces
This area studies the influence of technological parameters on the topography of a machined surface for different types of materials. It also finds links between force action, vibration, working pressure fluctuation, acoustic emission and topography of the machined surface. Analysis is carried out by applying new layers to on the machined surface.
-
New areas of high-speed water jet utilization
This research is oriented primarily around using the abrasive water jet in different machining techniques (turning, milling, polishing, drilling, etc.) in difficult-to-machine and non-machinable materials, such as composites, ceramics, high-strength alloys, glass, rocks, etc. It also studies the the utilization of high-speed water jets for ultra-fine grinding and disintegration of materials (primarily geomaterials) to produce submicron particles.
Important scientific achievements
- The generation of a pulsating water jet for the disintegration of material
The result concerns the use of high pressure water jets for cutting and generally disintegrating materials. The generation of sufficiently high pressure pulsations in water upstream of the nozzle exit enables the creation of a pulsating liquid jet that emerges from the nozzle as a continuous stream which forms pulses at certain standoff distances from the nozzle exit. The advantage of such a pulsating jet over a continuous one is based on the fact that the initial impact of pulses on the target surface generates cyclically and an impact pressure that is several times higher than the stagnation pressure generated by the action of continuous jet under the same working conditions. In addition, the action of a pulsating jet also induces both fatigue and shear stresses in the target material due to the cyclic loading of the target surface and the radial high speed flow across the surface. This further improves the efficiency of the pulsating liquid jet in comparison with the continuous flow. An original method of generating a pulsating liquid jet was recently developed and extensively tested. The method is based on the generation of acoustic waves by an acoustic actuator on the pressurised liquid and their transmission via a pressurised system to the nozzle. Research into the fundamentals of the excitation process and the propagation of acoustic waves (and/or high-frequency pressure pulsations) in liquid via a high-pressure system and their influence on the formation and properties of a pulsating liquid jet was crowned by the granting of a Czech patent and the completion of a license agreement for the manufacture of one piece of an acoustic generator of pressurised pulsations. At present, the cooperative agreement with an industrial partner which will lead to the signing of an exclusive licence agreement for the manufacture, use and sale of generators based on the above mentioned patent is being prepared.
The achievement was included in most important results of basic and targeted research of the Academy of Sciences in 2008 (see Annual Report of the Academy of Sciences of the Czech Republic in 2008 , in czech).
- Removal of degraded surface layers of concrete by high-speed water jets
Laboratory experiments concerned with the removal of degraded surface layers of concrete by high-speed continuous and pulsating water jets, were prepared in cooperation with Brno University of Technology, Faculty of Civil Engineering and VSB - Technical University of Ostrava, Institute of Physics. Concrete blocks of precisely-defined properties were created; some of them were stored or tested by cyclic loading in different corrosive environments (freezing effect, the effect of chemical de-freezing agents, long-term effects of chlorides, sulphates and nitrates). Several testing samples were left as reference samples, i.e. not exposed to any corrosive environment. The pulsating jet achieved a higher efficiency in all cases compared to a continuous jet under the same working conditions. However, the ratio of volume removed from the concrete test sample by both pulsating and continuous jets varied considerably according to type and degree of sample degradation and the cutting parameters. While continuous jets removed only the upper part of the cement paste, pulsating jets penetrated deeper and removed cement paste to aggregates at given testing conditions. Thus, pulsating jets are able to remove selectively degraded concrete layer and preserve “healthy concrete“ following the application of repair coatings and mortars also at low water pressures. A higher roughness of the concrete substrate treated by pulsating jets leads to better adhesion of newly applied layers.
- Numerical models of high pressure systems with an acoustic actuator
Numerical models of high pressure systems with an integrated acoustic actuator of high pressure pulsations were created. They allowed for the theoretical study of the processes of excitation and propagation of pressurised pulsations. Results of numerical simulation of pressurised pulsations demonstrate that relatively complicated geometries with one or two L-bows or relatively long liquid waveguide allow propagation of pressure pulsations from source to nozzle. The intensity of pulsations upstream from the nozzle exit can be substantially affected by defining the dimensions of separate parts of the high-pressure system and its tuning to resonance.
- Visualization of the pulsating jet
A special method of visualization of pulsating water jets based on the application of stroboscopic effect was elaborated. The frequency of stroboscope flashing is controlled by the frequency of the pressure pulsations in the high-pressure system which generates the pulsating jet. The visualization is used to study the influence of operating parameters and the geometric configuration of the acoustic generator of pressure pulsations on the formation and the morphology of the pulsating water jets.
- Abrasives for high-speed water jet technologies
Abrasive materials were evaluated from both mineralogical and petrological points of view. Their behaviour during the process of abrasive water jet generation and its action on the material to be cut was also looked at. Methodologies for the assessment of the initial properties of abrasive concentrates, their cutting efficiency in reference materials and the wearing effects on the focusing tube were developed. This was together with a methodology for description and morphological analysis of grains and cutting kerfs in macro- and micro-scales by image analysis. The determination of biological noxiousness of the respirable dust fraction, which results from the disintegration of natural and synthetic abrasives and minerals of the quartz group during application of abrasive water jet,represents another original result of the research. The work contributed to the formulation of both enduring problems and new themes for further research in the above mentioned area.
Technical equipment
- High pressure pump based on unit Hammelmann equipped with intensifier Flow (maximum operating pressure 380 MPa, max. flow rate up to 3.5 liters per minute) including accessories (filtration unit, high-pressure tubes, etc.)
- High pressure pump PTV 37-60 (one intensifier, maximum operating pressure 415 MPa, maximum flow rate up to 3.68 liters per minute) including accessories
- High-pressure plunger pump KUNZ Hranice (maximum operating pressure 120 MPa, max. flow rate up to 45 liters per minute)
- X-Y cutting system Nessap 1000-V specially designed for water jet and abrasive water jet cutting
- X-Y CNC cutting system WJ2020-1Z-D-PJ 2000 x 2000 mm with swing diamond cutting head specially designed for water jet and abrasive water jet cutting
- Three-component dynamometer Kistler with charge amplifier
- Four highly sensitive piezoelectric pressure sensors Kistler with charge amplifiers
- Patented sensor for measurement of the jet stagnation force (patent No. PV 7884-1988)
- Acoustic generator of pulsating jet 20 kHz
- Acoustic generator of pulsating jet 40 kHz
- Stroboscopic device for visualization of pulsating jet
- Measuring station based on notebook equipped with multifunction DAQ device National Instruments (16-bit) and LabVIEW Full Development System software
- Device for measurement of rock abrasiveness according to standard ON 44 1121
- Laser Particle Sizer analysette 22 NanoTec wet - Fritsch
- Workstation FSC CELSIUS R650: 2 processors Quad-Core Xeon X5460 3.16 GHz, RAM 32 GB, HDD 2x 500 GB
- CFD software ANSYS for simulation and modelling of high speed fluid jet
Projects solved in last years
- International project CNR Italy – AV CR Cutting and disintegration of hard rocks with water jet assistance. Special instruments, approaches and evaluation of cutting and disintegration performance (2004-2006), CSGM CNR, Cagliari, Italy.
- International project CNR Italy – AV CR Rock cutting with assistance of high-energy water jet. Preparation of special methods of measurement and evaluation of cutting performance (2001-2003), CSGM CNR, Cagliari, Italy.
- Project of bilateral cooperation between AVCR and PAN Poland: Application of advanced research methods to description of rocks and their discontinuities (Instytut Mechaniky Gorotworu PAN Krakow, Poland, 2006-2008).
- International project of Czecho-Slovak scientific and technical cooperation in the frame of program Kontakt No. 169 Development of ultrasonic generator based on piezoelectric transducer for modulation of high-speed water jet (2004-2005), Ecoson s.r.o. Nove Mesto nad Vahom, Slovakia.
- International project of Czecho-Slovak scientific and technical cooperation in the frame of program Kontakt No. 206 Development of ultrasonic nozzle based on hydrodynamic generator for generation of modulated high-speed water jets (2002-2003), Ecoson s.r.o. Nove Mesto nad Vahom, Slovakia.
- Grant project GA CR No. 105/03/0183 Development of novel technique for quarrying and cutting of ornamental stones, evaluated as excellent.
- Grant project GA AVCR No. 1QS300860501 Novel technique for cleaning and removal of surface layers and repair of concrete structures, evaluated as excellent.
- Grant project GA CR No. 105/00/0235 Forced modulation of water jet by ultrasonic, evaluated as excellent.
- Grant project GA AVCR No. A2086001 Hydrodynamic generator of pulsed jets.
- International project INCO Copernicus No. IC 15 CT98 0821 Abrasive water jet cutting, a clean technology. (9 partners from Germany, Italy, Poland, Hungary, Romania, Slovenia, 1999-2002).
Selected publications
- Foldyna, J., Heiniger, K. Mettler, S., Sitek, L., Scucka, J. Enhancing of Water Jet Effects by Pulsations. Manufacturing Engineering 4/2007,. pp. 30-33, ISSN 1335-7972.
- Nowakowski, A., Młynarczuk, M., Sitek, L., Foldyna, J. Wytrzymałość skały na rozciąganie – porownanie wynikow testu bezpośredniego rozciągania i testu brazylijskiego (Tensile strength of rock – comparison of results of direct tension test and Brazilian test). Sbornik vedeckych praci VSB-TU c. 2, roc. IX, rada stavebni, VSB-TU 2009, pp. 201 – 217, ISBN 978-80-248-2119-1, ISSN 1213-1962.
- Foldyna, J. Sitek, L. Scucka, J. Martinec, P. Valicek, J. Palenikova, K. Effects of pulsating water jet impact on aluminium surface. Journal of material processing technology Vol. 209, Iss. 20 (2009), pp. 6174–6180. Elsevier, 2009. ISSN 0924-0136.
- Bortolussi, A., Foldyna, J., Ciccu, R., Scucka, J., Martinec, P., Sitek, L. Ornamental stone surface treatment by pulsating water jets. 9th Pacific Rim Int. Conf. on Water Jetting Technology, 20. - 23. 11. 2009, Koriyama, Japonsko, IAP,Ltd. 2009, pp. 189-193, ISBN 4-902590-14-8.
- Sitek, L., Foldyna, J., Scucka, J., Martinec, P., Bodnarova, L., Hela, R. Utilization of Potential of Pulsating Jets for Removal of Concrete Layers. 9th Pacific Rim Int. Conf. on Water Jetting Technology, 20. - 23. 11. 2009, Koriyama, Japonsko, IAP,Ltd. 2009, pp. 181-187, ISBN 4-902590-14-8.
- Scucka, J., Foldyna, J., Sitek, L., Martinec, P., Valicek. J. Testing of fan jet nozzles for pulsating jets generation. 9th Pacific Rim Int. Conf. on Water Jetting Technology, 20. - 23. 11. 2009, Koriyama, Japonsko, IAP, Ltd. 2009, pp. 195-200, ISBN 4-902590-14-8.
- Foldyna, J. Research and development of pulsating water jets. In Pacific Rim International Conference on Water Jetting Technology /9./ Proceedings. Koriyama: Water Jet Technology Society of Japan, 2009. S. 171-179. ISBN 4-902590-14-8.
- Hlavacek, P., Valicek, J., Hloch, S., Gregr, M., Foldyna, J., Kozak, D., Sitek, L., Kusnerova, M., Zelenak, M. Measurement of Fine Grain Copper Surface Texture Created by Abrasive Water Jet Cutting. Strojarstvo 51(4), 2009, 273-279, ISSN 0562-1887.