Dawid Majewski | UG - Academia.edu (original) (raw)
Papers by Dawid Majewski
The Arctic region has experienced rapid changes in the last few decades. The Arctic coasts in tim... more The Arctic region has experienced rapid changes in the last few decades. The Arctic coasts in times of progressing global warming are exceptionally vulnerable to erosion. Arctic sea-ice extent is decreasing dramatically leaving coasts exposed to destructive action of waves. The lack of sea ice causes a dramatic increase of wave energy reaching coastline. In order to provide insight into coastal changes in Arctic areas, field measurements were carried out in the area of Calypsobyen, Bellsund, west Spitsbergen. Data of freesurface elevation, wave orbital velocities, water currents and bathymetry were collected during expedition in the western Spitsbergen. In the frame of this study a detailed analysis of wave field were performed. The collected database constitute unique and valuable source of information on Arctic wave climate.
Water, Aug 2, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Water
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Volume 9: Offshore Geotechnics, Jun 5, 2022
Water
The purpose of the study was to collect experimental data on the vertical structure of sediment f... more The purpose of the study was to collect experimental data on the vertical structure of sediment fluxes during the wave crest and trough phase over sloped bed. The first stage of the experimental work included measurements of these fluxes using the particle image method, while the second stage, measurements of sediment transport rates and granulometric distributions of sediments collected in the traps on both sides of the sloped initial area. The experimental data were compared both with the results collected previously over flat bed as well as with a theoretical analysis based on a three-layer model of graded sediment transport. This model does not take into account the effects related to the presence of fine and very fine fractions and neglects the effects related to the bed slope, i.e., to gravitational forces and to additional pressure gradients. Hence, a modification of this model is proposed that is based on four coefficients that corrected for sediment fluxes over sloped bed. ...
Water
The purpose of the study was to collect experimental data on the vertical structure of sediment f... more The purpose of the study was to collect experimental data on the vertical structure of sediment fluxes during the wave crest and trough phase. The first stage of the experimental work included measurements of these fluxes using the particle image method, while in the second stage, measurements of sediment transport rates and granulometric distributions of sediments were collected in the traps on both sides of the initial area. The experimental data were compared with the results of a theoretical analysis based on a three-layer model of graded sediment transport. The comparison of the calculations with the measurements was conducted separately for fluxes of fine and very fine fractions in the diameter range di < 0.20 mm, coarse, and total fractions all outgoing in the crest and trough phase from the initial area and deposited in adjacent control areas. As this model did not take into account both the effects of vertical mixing and the phase-lag effects related to the presence of f...
Volume 9: Offshore Geotechnics
This paper presents the results of an experimental study of seabed liquefaction under progressive... more This paper presents the results of an experimental study of seabed liquefaction under progressive waves. Firstly, during preliminary tests, the physical and mechanical parameters of the soil selected as the subgrade material were determined. A series of monotonic triaxial shear tests were carried out at different initial void ratios and mean effective stresses. The susceptibility of soil samples to liquefaction was estimated. The results were used to design experiments in a wave flume. Their main purpose was to study the effect of wave height on wave-induced liquefaction. The experiments were carried out in a wave flume that is 64.1 m long, 0.6 m wide, and 1.4 m high, in a specially built experimental stand located 5.0 m from the wave generator below the flume bottom. Wave propagation was conducted over constant water depth which was equal h = 0.5 m. The wave surface elevation was measured by resistance type wave gauges. The pore-water pressure was measured by transducers located in...
Przegląd Spawalnictwa - Welding Technology Review, 2016
Jakość w lutowaniu twardym i lutospawaniu-kwalifikowanie technologii i personelu, metody badań Th... more Jakość w lutowaniu twardym i lutospawaniu-kwalifikowanie technologii i personelu, metody badań The quality of brazing and braze welding-qualification of technology and personnel, test methods Dr inż. Andrzej Winiowski, prof. nzw. w IS; dr inż. Dawid Majewski-Instytut Spawalnictwa Gliwice.
The paper presents the experimental test setup and measurement method of hydrodynamic force gener... more The paper presents the experimental test setup and measurement method of hydrodynamic force generated on the rotating cylinder (rotor) under uniform flow including the free surface effect. The experimental test setup was a unique construction installed in the flume tank equipped with advanced flow generating and measuring systems. The test setup consisted of a bearing mounted platform with rotor drive and sensors measuring the hydrodynamic force. The low length to diameter ratio cylinders were selected as models of bow rotor rudders of a shallow draft river barge. The rotor dynamics was tested for the rotational speeds up to 550 rpm and water current velocity up to 0.85 m/s. The low aspect ratio of the cylinder and free surface effect had significant impacts on the phenomena influencing the generated hydrodynamic force. The effects of the rotor length to diameter ratio, rotational velocity to flow velocity ratio, and the Reynolds number on the lift force were analyzed. The validatio...
W pracy przedstawiono pierwsze w Polsce eksperymentalne badania współoddziaływania fal powierzchn... more W pracy przedstawiono pierwsze w Polsce eksperymentalne badania współoddziaływania fal powierzchniowych z prądem wodnym. Zaprezentowano wyniki pomiarów wykonanych dla różnych prędkości i kierunków prądu oraz parametrów fali. Opisano zależności pomiędzy kierunkiem i prędkością prądu, a okresem fali. Rozważano ich wpływ na zmiany w wychyleniu powierzchni swobodnej oraz na amplitudy prędkości przepływu. Przedstawiona została również analiza czasu propagacji fali w przypadku jej interakcji z prądem. The paper presents experimental study of interaction of surface water waves with currents, conducted for the first time in Poland. The results of measurements taken for different speeds and directions of current and different wave parameters are presented. The relationship between the current direction, current velocity and the period of the wave is investigated. Its effect on free surface elevation and on the current velocity amplitude are described. In the case of interaction with the curr...
The effect of current on the formation of freak waves was investigated by conducting laboratory e... more The effect of current on the formation of freak waves was investigated by conducting laboratory experiments in a wave flume. The generation of freak-type waves in a wave flume is based on the method of focusing of waves propagating in a wave group. The investigation show that the formation of a freak waves is strongly affected by the direction of a current, current magnitude and relative phase between wave train components. The recorded data show that an opposing current increases a freak wave crest height and a following current reduces crest height. Moreover, the results show that a current has an noticeable effect on the location of freak wave formation. Recorded data show that a current results in a shift in space of the freak wave formation in comparisons with theoretical predictions. Additionally, the results show that a current has an significant effect on a formation time of a freak wave. In particular, recorded data show that the opposing current causes faster freak wave fo...
The effect of current on the formation of freak waves was investigated by conducting laboratory e... more The effect of current on the formation of freak waves was investigated by conducting laboratory experiments in a wave flume. The generation of freak-type waves in a wave flume is based on the method of focusing of waves propagating in a wave group. The investigation show that the formation of a freak waves is strongly affected by the direction of a current, current magnitude and relative phase between wave train components. The recorded data show that an opposing current increases a freak wave crest height and a following current reduces crest height. Moreover, the results show that a current has an noticeable effect on the location of freak wave formation. Recorded data show that a current results in a shift in space of the freak wave formation in comparisons with theoretical predictions. Additionally, the results show that a current has an significant effect on a formation time of a freak wave. In particular, recorded data show that the opposing current causes faster freak wave fo...
W pracy przedstawiono pierwsze w Polsce eksperymentalne badania współoddziaływania fal powierzchn... more W pracy przedstawiono pierwsze w Polsce eksperymentalne badania współoddziaływania fal powierzchniowych z prądem wodnym. Zaprezentowano wyniki pomiarów wykonanych dla różnych prędkości i kierunków prądu oraz parametrów fali. Opisano zależności pomiędzy kierunkiem i prędkością prądu, a okresem fali. Rozważano ich wpływ na zmiany w wychyleniu powierzchni swobodnej oraz na amplitudy prędkości przepływu. Przedstawiona została również analiza czasu propagacji fali w przypadku jej interakcji z prądem. The paper presents experimental study of interaction of surface water waves with currents, conducted for the first time in Poland. The results of measurements taken for different speeds and directions of current and different wave parameters are presented. The relationship between the current direction, current velocity and the period of the wave is investigated. Its effect on free surface elevation and on the current velocity amplitude are described. In the case of interaction with the curr...
The effect of current on the formation of freak waves was investigated by conducting laboratory e... more The effect of current on the formation of freak waves was investigated by conducting laboratory experiments in a wave flume. The generation of freak-type waves in a wave flume is based on the method of focusing of waves propagating in a wave group. The investigation show that the formation of a freak waves is strongly affected by the direction of a current, current magnitude and relative phase between wave train components. The recorded data show that an opposing current increases a freak wave crest height and a following current reduces crest height. Moreover, the results show that a current has an noticeable effect on the location of freak wave formation. Recorded data show that a current results in a shift in space of the freak wave formation in comparisons with theoretical predictions. Additionally, the results show that a current has an significant effect on a formation time of a freak wave. In particular, recorded data show that the opposing current causes faster freak wave fo...
The Arctic region has experienced rapid changes in the last few decades. The Arctic coasts in tim... more The Arctic region has experienced rapid changes in the last few decades. The Arctic coasts in times of progressing global warming are exceptionally vulnerable to erosion. Arctic sea-ice extent is decreasing dramatically leaving coasts exposed to destructive action of waves. The lack of sea ice causes a dramatic increase of wave energy reaching coastline. In order to provide insight into coastal changes in Arctic areas, field measurements were carried out in the area of Calypsobyen, Bellsund, west Spitsbergen. Data of freesurface elevation, wave orbital velocities, water currents and bathymetry were collected during expedition in the western Spitsbergen. In the frame of this study a detailed analysis of wave field were performed. The collected database constitute unique and valuable source of information on Arctic wave climate.
Water, Aug 2, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Water
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Volume 9: Offshore Geotechnics, Jun 5, 2022
Water
The purpose of the study was to collect experimental data on the vertical structure of sediment f... more The purpose of the study was to collect experimental data on the vertical structure of sediment fluxes during the wave crest and trough phase over sloped bed. The first stage of the experimental work included measurements of these fluxes using the particle image method, while the second stage, measurements of sediment transport rates and granulometric distributions of sediments collected in the traps on both sides of the sloped initial area. The experimental data were compared both with the results collected previously over flat bed as well as with a theoretical analysis based on a three-layer model of graded sediment transport. This model does not take into account the effects related to the presence of fine and very fine fractions and neglects the effects related to the bed slope, i.e., to gravitational forces and to additional pressure gradients. Hence, a modification of this model is proposed that is based on four coefficients that corrected for sediment fluxes over sloped bed. ...
Water
The purpose of the study was to collect experimental data on the vertical structure of sediment f... more The purpose of the study was to collect experimental data on the vertical structure of sediment fluxes during the wave crest and trough phase. The first stage of the experimental work included measurements of these fluxes using the particle image method, while in the second stage, measurements of sediment transport rates and granulometric distributions of sediments were collected in the traps on both sides of the initial area. The experimental data were compared with the results of a theoretical analysis based on a three-layer model of graded sediment transport. The comparison of the calculations with the measurements was conducted separately for fluxes of fine and very fine fractions in the diameter range di < 0.20 mm, coarse, and total fractions all outgoing in the crest and trough phase from the initial area and deposited in adjacent control areas. As this model did not take into account both the effects of vertical mixing and the phase-lag effects related to the presence of f...
Volume 9: Offshore Geotechnics
This paper presents the results of an experimental study of seabed liquefaction under progressive... more This paper presents the results of an experimental study of seabed liquefaction under progressive waves. Firstly, during preliminary tests, the physical and mechanical parameters of the soil selected as the subgrade material were determined. A series of monotonic triaxial shear tests were carried out at different initial void ratios and mean effective stresses. The susceptibility of soil samples to liquefaction was estimated. The results were used to design experiments in a wave flume. Their main purpose was to study the effect of wave height on wave-induced liquefaction. The experiments were carried out in a wave flume that is 64.1 m long, 0.6 m wide, and 1.4 m high, in a specially built experimental stand located 5.0 m from the wave generator below the flume bottom. Wave propagation was conducted over constant water depth which was equal h = 0.5 m. The wave surface elevation was measured by resistance type wave gauges. The pore-water pressure was measured by transducers located in...
Przegląd Spawalnictwa - Welding Technology Review, 2016
Jakość w lutowaniu twardym i lutospawaniu-kwalifikowanie technologii i personelu, metody badań Th... more Jakość w lutowaniu twardym i lutospawaniu-kwalifikowanie technologii i personelu, metody badań The quality of brazing and braze welding-qualification of technology and personnel, test methods Dr inż. Andrzej Winiowski, prof. nzw. w IS; dr inż. Dawid Majewski-Instytut Spawalnictwa Gliwice.
The paper presents the experimental test setup and measurement method of hydrodynamic force gener... more The paper presents the experimental test setup and measurement method of hydrodynamic force generated on the rotating cylinder (rotor) under uniform flow including the free surface effect. The experimental test setup was a unique construction installed in the flume tank equipped with advanced flow generating and measuring systems. The test setup consisted of a bearing mounted platform with rotor drive and sensors measuring the hydrodynamic force. The low length to diameter ratio cylinders were selected as models of bow rotor rudders of a shallow draft river barge. The rotor dynamics was tested for the rotational speeds up to 550 rpm and water current velocity up to 0.85 m/s. The low aspect ratio of the cylinder and free surface effect had significant impacts on the phenomena influencing the generated hydrodynamic force. The effects of the rotor length to diameter ratio, rotational velocity to flow velocity ratio, and the Reynolds number on the lift force were analyzed. The validatio...
W pracy przedstawiono pierwsze w Polsce eksperymentalne badania współoddziaływania fal powierzchn... more W pracy przedstawiono pierwsze w Polsce eksperymentalne badania współoddziaływania fal powierzchniowych z prądem wodnym. Zaprezentowano wyniki pomiarów wykonanych dla różnych prędkości i kierunków prądu oraz parametrów fali. Opisano zależności pomiędzy kierunkiem i prędkością prądu, a okresem fali. Rozważano ich wpływ na zmiany w wychyleniu powierzchni swobodnej oraz na amplitudy prędkości przepływu. Przedstawiona została również analiza czasu propagacji fali w przypadku jej interakcji z prądem. The paper presents experimental study of interaction of surface water waves with currents, conducted for the first time in Poland. The results of measurements taken for different speeds and directions of current and different wave parameters are presented. The relationship between the current direction, current velocity and the period of the wave is investigated. Its effect on free surface elevation and on the current velocity amplitude are described. In the case of interaction with the curr...
The effect of current on the formation of freak waves was investigated by conducting laboratory e... more The effect of current on the formation of freak waves was investigated by conducting laboratory experiments in a wave flume. The generation of freak-type waves in a wave flume is based on the method of focusing of waves propagating in a wave group. The investigation show that the formation of a freak waves is strongly affected by the direction of a current, current magnitude and relative phase between wave train components. The recorded data show that an opposing current increases a freak wave crest height and a following current reduces crest height. Moreover, the results show that a current has an noticeable effect on the location of freak wave formation. Recorded data show that a current results in a shift in space of the freak wave formation in comparisons with theoretical predictions. Additionally, the results show that a current has an significant effect on a formation time of a freak wave. In particular, recorded data show that the opposing current causes faster freak wave fo...
The effect of current on the formation of freak waves was investigated by conducting laboratory e... more The effect of current on the formation of freak waves was investigated by conducting laboratory experiments in a wave flume. The generation of freak-type waves in a wave flume is based on the method of focusing of waves propagating in a wave group. The investigation show that the formation of a freak waves is strongly affected by the direction of a current, current magnitude and relative phase between wave train components. The recorded data show that an opposing current increases a freak wave crest height and a following current reduces crest height. Moreover, the results show that a current has an noticeable effect on the location of freak wave formation. Recorded data show that a current results in a shift in space of the freak wave formation in comparisons with theoretical predictions. Additionally, the results show that a current has an significant effect on a formation time of a freak wave. In particular, recorded data show that the opposing current causes faster freak wave fo...
W pracy przedstawiono pierwsze w Polsce eksperymentalne badania współoddziaływania fal powierzchn... more W pracy przedstawiono pierwsze w Polsce eksperymentalne badania współoddziaływania fal powierzchniowych z prądem wodnym. Zaprezentowano wyniki pomiarów wykonanych dla różnych prędkości i kierunków prądu oraz parametrów fali. Opisano zależności pomiędzy kierunkiem i prędkością prądu, a okresem fali. Rozważano ich wpływ na zmiany w wychyleniu powierzchni swobodnej oraz na amplitudy prędkości przepływu. Przedstawiona została również analiza czasu propagacji fali w przypadku jej interakcji z prądem. The paper presents experimental study of interaction of surface water waves with currents, conducted for the first time in Poland. The results of measurements taken for different speeds and directions of current and different wave parameters are presented. The relationship between the current direction, current velocity and the period of the wave is investigated. Its effect on free surface elevation and on the current velocity amplitude are described. In the case of interaction with the curr...
The effect of current on the formation of freak waves was investigated by conducting laboratory e... more The effect of current on the formation of freak waves was investigated by conducting laboratory experiments in a wave flume. The generation of freak-type waves in a wave flume is based on the method of focusing of waves propagating in a wave group. The investigation show that the formation of a freak waves is strongly affected by the direction of a current, current magnitude and relative phase between wave train components. The recorded data show that an opposing current increases a freak wave crest height and a following current reduces crest height. Moreover, the results show that a current has an noticeable effect on the location of freak wave formation. Recorded data show that a current results in a shift in space of the freak wave formation in comparisons with theoretical predictions. Additionally, the results show that a current has an significant effect on a formation time of a freak wave. In particular, recorded data show that the opposing current causes faster freak wave fo...