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The interfacial wave structure of the liquid film in both upward and downward annular gas-liquid flows in an 11.7 mm pipe were investigated using the Brightness Based Laser Induced Fluorescence technique (BBLIF). Film thickness measurements were carried out with high spatial and temporal resolution between 330 and 430 mm from the inlet, where the properties of disturbance waves are almost stabilised. Using a tracking algorithm to detect disturbance waves, a full characterisation in terms of their velocity, frequency, longitudinal size and spacing was carried out. Direct comparison between both flow orientations while testing the same flow conditions shows that although the flow orientation does not affect the velocity of disturbance waves, the fraction of film surface occupied by the disturbance waves is smaller in upwards flow. Thus, more liquid travels in the base film in upwards flow, which is consistent with the base film thickness measurements. These observations, together with qualitatively different behaviour of ripple wave velocity in upwards and downwards flows, studied using 2D Fourier analysis, indicate that the role of gravity is much more important on the base film than on disturbance waves. This supposedly occurs due to a local decrease in the interfacial shear stress on the base film surface because of the resistance of the disturbance waves to the gas stream in upward flow.

The flow of a liquid film sheared by high velocity gas stream in a horizontal rectangular duct was investigated using a high-speed laser-induced fluorescence technique. Measurements of local film thickness were resolved in both longitudinal and transverse coordinates with high spatial and temporal resolution. It was found that the generation of fast and slow ripples by the disturbance waves was qualitatively the same as it was observed earlier in completely different conditions. The transverse size and curvature of the disturbance waves and ripples were measured. A relationship between the three-dimensional structure of ripples on top of disturbance waves and the two mechanisms of liquid entrainment, known as ‘bag break-up’ and ‘ligament break-up’, is proposed.

Aeroengine bearing chambers are geometrically complex, typically containing shafts, bearings, seals and stationary components. Oil is supplied for lubrication and cooling and so the chamber contains a highly rotating two-phase (oil/air) flow where the oil is typically present as droplets, ligaments, mist and films. These films may be thick or thin and film speed varies with chamber location. It is desirable to know a priori the outcome of a droplet-film impact event in terms of mass, momentum and energy transfer. There is a significant body of research on the interaction between droplets and static films. The experimental parameter space has been characterised on the basis of film thickness and impact parameter to predict the outcome of an impingement. The impingement of droplets on moving films has only begun to be investigated over the last decade and consequently models have not yet been developed and the parameter space has barely begun to be characterised. Within this paper results are presented from an experimental study in which water droplets of 3 mm and 3.8 mm at 20°C falling under the influence of gravity impinged onto water films flowing down an inclined plane. Film temperature was 30°C and film thicknesses were between 2.3 mm and 4.2 mm. High speed imaging was used to determine the impingement outcomes and cavity morphology. A high speed infrared camera was used to determine the extent of the thermally affected region and its temperature behaviour. We find that by using the resultant droplet velocity (combining droplet and film velocities) the film impingement outcomes can be characterised into regions very similar to those for static films. The data is presented as a function of splashing parameter and non-dimensional film thickness. It was observed that for these impacts on supercritical films (Fr > 1) there is less propensity for secondary droplet formation through jet breakup than on static and subcritical films (Fr < 1). Data was obtained for extent

Melt ejection is the dominant material removal mechanism in long, ms, pulse laser drilling of metals, a process with applications such as the drilling of cooling holes in turbine blades. Droplets of molten material are ejected through the entrance hole and, after breakthrough, through the exit hole. High speed filming is used to study the ejected material in order to better understand how this debris may interact with material in the immediate vicinity of the drilled hole. Existing studies have quantified various aspects of melt ejection, however they usually focus on ejection through the entrance hole. This work concentrates on rear melt ejection and is relevant to issues such as rear wall impingement. A 2kW IPG 200S fibre laser is used to drill mild steel. High speed filming is combined with image analysis to characterise the rearward-ejected material. Particle size and velocity data is presented as a function of drilling parameters. It is concluded that high speed filming combined with image analysis and proper consideration of process limitations and optimisation strategies can be a powerful tool in understanding resultant debris distributions.

Permanent magnet synchronous generators (PMSG) are at the core of small scale wind power generators manufactured by a wide range of manufacturers in different configurations: vertical or horizontal axis blades, with various geometries and aerodynamics of the blades; by installing these small scale wind turbines in very large numbers at household levels, it is expected that these will make a positive contribution to the increase of renewable energy generation, reducing the use of fossil fuels that are blamed for climate change. However, a proper evaluation of the technical specification of these small scale wind generators in various weather conditions is necessary in order to assess the full potential of benefits. This paper reports on the implementation and testing of a power electronic dump load that allows continuously adjustable loading of a PMSG with sinusoidal currents and have the capability to self synchronize to its frequency/speed whilst avoiding transient/loosing of synchronism.

The results of an experimental study on droplet impactions in the flow of a gas-sheared liquid film are presented. In contrast to most similar studies, the impacting droplets were entrained from film surface by the gas stream. The measurements provide film thickness data, resolved in both longitudinal and transverse coordinates and in time together with the images of droplets above the interface and images of gas bubbles entrapped by liquid film. The parameters of impacting droplets were measured together with the local liquid film thickness. Two main scenarios of droplet-film interaction, based on type of film perturbation, are identified; the parameter identifying which scenario occurs is identified as the angle of impingement. At large angles an asymmetric crater appears on film surface; at shallow angles a long, narrow furrow appears. The most significant difference between the two scenarios is related to possible impact outcome: craters may lead to creation secondary droplets, whereas furrows are accompanied by entrapment of gas bubbles into the liquid film. In addition, occurrence of partial survival of impacting droplet is reported.

The results of an experimental study on droplet impactions in the flow of a gas-sheared liquid film are presented. In contrast to most similar studies, the impacting droplets were entrained from film surface by the gas stream. The measurements provide film thickness data, resolved in both longitudinal and transverse coordinates and in time together with the images of droplets above the interface and images of gas bubbles entrapped by liquid film. The parameters of impacting droplets were measured together with the local liquid film thickness. Two main scenarios of droplet-film interaction, based on type of film perturbation, are identified; the parameter identifying which scenario occurs is identified as the angle of impingement. At large angles an asymmetric crater appears on film surface; at shallow angles a long, narrow furrow appears. The most significant difference between the two scenarios is related to possible impact outcome: craters may lead to creation secondary droplets, whereas furrows are accompanied by entrapment of gas bubbles into the liquid film. In addition, occurrence of partial survival of impacting droplet is reported.

Melt ejection is the dominant material removal mechanism in long, ms, pulse laser drilling of metals, a process with applications such as the drilling of cooling holes in turbine blades. Droplets of molten material are ejected through the entrance hole and, after breakthrough, through the exit hole. High speed filming is used to study the ejected material in order to better understand how this debris may interact with material in the immediate vicinity of the drilled hole. Existing studies have quantified various aspects of melt ejection, however they usually focus on ejection through the entrance hole. This work concentrates on rear melt ejection and is relevant to issues such as rear wall impingement. A 2kW IPG 200S fibre laser is used to drill mild steel. High speed filming is combined with image analysis to characterise the rearward-ejected material. Particle size and velocity data is presented as a function of drilling parameters. It is concluded that high speed filming combined with image analysis and proper consideration of process limitations and optimisation strategies can be a powerful tool in understanding resultant debris distributions.

Aeroengine bearing chambers are geometrically complex, typically containing shafts, bearings, seals and stationary components. Oil is supplied for lubrication and cooling and so the chamber contains a highly rotating two-phase (oil/air) flow where the oil is typically present as droplets, ligaments, mist and films. These films may be thick or thin and film speed varies with chamber location. It is desirable to know a priori the outcome of a droplet-film impact event in terms of mass, momentum and energy transfer. There is a significant body of research on the interaction between droplets and static films. The experimental parameter space has been characterised on the basis of film thickness and impact parameter to predict the outcome of an impingement. The impingement of droplets on moving films has only begun to be investigated over the last decade and consequently models have not yet been developed and the parameter space has barely begun to be characterised. Within this paper results are presented from an experimental study in which water droplets of 3 mm and 3.8 mm at 20°C falling under the influence of gravity impinged onto water films flowing down an inclined plane. Film temperature was 30°C and film thicknesses were between 2.3 mm and 4.2 mm. High speed imaging was used to determine the impingement outcomes and cavity morphology. A high speed infrared camera was used to determine the extent of the thermally affected region and its temperature behaviour. We find that by using the resultant droplet velocity (combining droplet and film velocities) the film impingement outcomes can be characterised into regions very similar to those for static films. The data is presented as a function of splashing parameter and non-dimensional film thickness. It was observed that for these impacts on supercritical films (Fr > 1) there is less propensity for secondary droplet formation through jet breakup than on static and subcritical films (Fr < 1). Data was obtained for extent

The flow of a liquid film sheared by high velocity gas stream in a horizontal rectangular duct was investigated using a high-speed laser-induced fluorescence technique. Measurements of local film thickness were resolved in both longitudinal and transverse coordinates with high spatial and temporal resolution. It was found that the generation of fast and slow ripples by the disturbance waves was qualitatively the same as it was observed earlier in completely different conditions. The transverse size and curvature of the disturbance waves and ripples were measured. A relationship between the three-dimensional structure of ripples on top of disturbance waves and the two mechanisms of liquid entrainment, known as ‘bag break-up’ and ‘ligament break-up’, is proposed.

Permanent magnet synchronous generators (PMSG) are at the core of small scale wind power generators manufactured by a wide range of manufacturers in different configurations: vertical or horizontal axis blades, with various geometries and aerodynamics of the blades; by installing these small scale wind turbines in very large numbers at household levels, it is expected that these will make a positive contribution to the increase of renewable energy generation, reducing the use of fossil fuels that are blamed for climate change. However, a proper evaluation of the technical specification of these small scale wind generators in various weather conditions is necessary in order to assess the full potential of benefits. This paper reports on the implementation and testing of a power electronic dump load that allows continuously adjustable loading of a PMSG with sinusoidal currents and have the capability to self synchronize to its frequency/speed whilst avoiding transient/loosing of synchronism.

The interfacial wave structure of the liquid film in both upward and downward annular gas-liquid flows in an 11.7 mm pipe were investigated using the Brightness Based Laser Induced Fluorescence technique (BBLIF). Film thickness measurements were carried out with high spatial and temporal resolution between 330 and 430 mm from the inlet, where the properties of disturbance waves are almost stabilised. Using a tracking algorithm to detect disturbance waves, a full characterisation in terms of their velocity, frequency, longitudinal size and spacing was carried out. Direct comparison between both flow orientations while testing the same flow conditions shows that although the flow orientation does not affect the velocity of disturbance waves, the fraction of film surface occupied by the disturbance waves is smaller in upwards flow. Thus, more liquid travels in the base film in upwards flow, which is consistent with the base film thickness measurements. These observations, together with qualitatively different behaviour of ripple wave velocity in upwards and downwards flows, studied using 2D Fourier analysis, indicate that the role of gravity is much more important on the base film than on disturbance waves. This supposedly occurs due to a local decrease in the interfacial shear stress on the base film surface because of the resistance of the disturbance waves to the gas stream in upward flow.

The results of an experimental study on droplet impactions in the flow of a gas-sheared liquid film are presented. In contrast to most similar studies, the impacting droplets were entrained from film surface by the gas stream. The measurements provide film thickness data, resolved in both longitudinal and transverse coordinates and in time together with the images of droplets above the interface and images of gas bubbles entrapped by liquid film. The parameters of impacting droplets were measured together with the local liquid film thickness. Two main scenarios of droplet-film interaction, based on type of film perturbation, are identified; the parameter identifying which scenario occurs is identified as the angle of impingement. At large angles an asymmetric crater appears on film surface; at shallow angles a long, narrow furrow appears. The most significant difference between the two scenarios is related to possible impact outcome: craters may lead to creation secondary droplets, whereas furrows are accompanied by entrapment of gas bubbles into the liquid film. In addition, occurrence of partial survival of impacting droplet is reported.

Aeroengine bearing chambers are geometrically complex, typically containing shafts, bearings, seals and stationary components. Oil is supplied for lubrication and cooling and so the chamber contains a highly rotating two-phase (oil/air) flow where the oil is typically present as droplets, ligaments, mist and films. These films may be thick or thin and film speed varies with chamber location. It is desirable to know a priori the outcome of a droplet-film impact event in terms of mass, momentum and energy transfer. There is a significant body of research on the interaction between droplets and static films. The experimental parameter space has been characterised on the basis of film thickness and impact parameter to predict the outcome of an impingement. The impingement of droplets on moving films has only begun to be investigated over the last decade and consequently models have not yet been developed and the parameter space has barely begun to be characterised. Within this paper results are presented from an experimental study in which water droplets of 3 mm and 3.8 mm at 20°C falling under the influence of gravity impinged onto water films flowing down an inclined plane. Film temperature was 30°C and film thicknesses were between 2.3 mm and 4.2 mm. High speed imaging was used to determine the impingement outcomes and cavity morphology. A high speed infrared camera was used to determine the extent of the thermally affected region and its temperature behaviour. We find that by using the resultant droplet velocity (combining droplet and film velocities) the film impingement outcomes can be characterised into regions very similar to those for static films. The data is presented as a function of splashing parameter and non-dimensional film thickness. It was observed that for these impacts on supercritical films (Fr > 1) there is less propensity for secondary droplet formation through jet breakup than on static and subcritical films (Fr < 1). Data was obtained for extent

The flow of a liquid film sheared by high velocity gas stream in a horizontal rectangular duct was investigated using a high-speed laser-induced fluorescence technique. Measurements of local film thickness were resolved in both longitudinal and transverse coordinates with high spatial and temporal resolution. It was found that the generation of fast and slow ripples by the disturbance waves was qualitatively the same as it was observed earlier in completely different conditions. The transverse size and curvature of the disturbance waves and ripples were measured. A relationship between the three-dimensional structure of ripples on top of disturbance waves and the two mechanisms of liquid entrainment, known as ‘bag break-up’ and ‘ligament break-up’, is proposed.

Melt ejection is the dominant material removal mechanism in long, ms, pulse laser drilling of metals, a process with applications such as the drilling of cooling holes in turbine blades. Droplets of molten material are ejected through the entrance hole and, after breakthrough, through the exit hole. High speed filming is used to study the ejected material in order to better understand how this debris may interact with material in the immediate vicinity of the drilled hole. Existing studies have quantified various aspects of melt ejection, however they usually focus on ejection through the entrance hole. This work concentrates on rear melt ejection and is relevant to issues such as rear wall impingement. A 2kW IPG 200S fibre laser is used to drill mild steel. High speed filming is combined with image analysis to characterise the rearward-ejected material. Particle size and velocity data is presented as a function of drilling parameters. It is concluded that high speed filming combined with image analysis and proper consideration of process limitations and optimisation strategies can be a powerful tool in understanding resultant debris distributions.

Permanent magnet synchronous generators (PMSG) are at the core of small scale wind power generators manufactured by a wide range of manufacturers in different configurations: vertical or horizontal axis blades, with various geometries and aerodynamics of the blades; by installing these small scale wind turbines in very large numbers at household levels, it is expected that these will make a positive contribution to the increase of renewable energy generation, reducing the use of fossil fuels that are blamed for climate change. However, a proper evaluation of the technical specification of these small scale wind generators in various weather conditions is necessary in order to assess the full potential of benefits. This paper reports on the implementation and testing of a power electronic dump load that allows continuously adjustable loading of a PMSG with sinusoidal currents and have the capability to self synchronize to its frequency/speed whilst avoiding transient/loosing of synchronism.

The interfacial wave structure of the liquid film in both upward and downward annular gas-liquid flows in an 11.7 mm pipe were investigated using the Brightness Based Laser Induced Fluorescence technique (BBLIF). Film thickness measurements were carried out with high spatial and temporal resolution between 330 and 430 mm from the inlet, where the properties of disturbance waves are almost stabilised. Using a tracking algorithm to detect disturbance waves, a full characterisation in terms of their velocity, frequency, longitudinal size and spacing was carried out. Direct comparison between both flow orientations while testing the same flow conditions shows that although the flow orientation does not affect the velocity of disturbance waves, the fraction of film surface occupied by the disturbance waves is smaller in upwards flow. Thus, more liquid travels in the base film in upwards flow, which is consistent with the base film thickness measurements. These observations, together with qualitatively different behaviour of ripple wave velocity in upwards and downwards flows, studied using 2D Fourier analysis, indicate that the role of gravity is much more important on the base film than on disturbance waves. This supposedly occurs due to a local decrease in the interfacial shear stress on the base film surface because of the resistance of the disturbance waves to the gas stream in upward flow.

The interfacial wave structure of the liquid film in both upward and downward annular gas-liquid flows in an 11.7 mm pipe were investigated using the Brightness Based Laser Induced Fluorescence technique (BBLIF). Film thickness measurements were carried out with high spatial and temporal resolution between 330 and 430 mm from the inlet, where the properties of disturbance waves are almost stabilised. Using a tracking algorithm to detect disturbance waves, a full characterisation in terms of their velocity, frequency, longitudinal size and spacing was carried out. Direct comparison between both flow orientations while testing the same flow conditions shows that although the flow orientation does not affect the velocity of disturbance waves, the fraction of film surface occupied by the disturbance waves is smaller in upwards flow. Thus, more liquid travels in the base film in upwards flow, which is consistent with the base film thickness measurements. These observations, together with qualitatively different behaviour of ripple wave velocity in upwards and downwards flows, studied using 2D Fourier analysis, indicate that the role of gravity is much more important on the base film than on disturbance waves. This supposedly occurs due to a local decrease in the interfacial shear stress on the base film surface because of the resistance of the disturbance waves to the gas stream in upward flow.

The results of an experimental study on droplet impactions in the flow of a gas-sheared liquid film are presented. In contrast to most similar studies, the impacting droplets were entrained from film surface by the gas stream. The measurements provide film thickness data, resolved in both longitudinal and transverse coordinates and in time together with the images of droplets above the interface and images of gas bubbles entrapped by liquid film. The parameters of impacting droplets were measured together with the local liquid film thickness. Two main scenarios of droplet-film interaction, based on type of film perturbation, are identified; the parameter identifying which scenario occurs is identified as the angle of impingement. At large angles an asymmetric crater appears on film surface; at shallow angles a long, narrow furrow appears. The most significant difference between the two scenarios is related to possible impact outcome: craters may lead to creation secondary droplets, whereas furrows are accompanied by entrapment of gas bubbles into the liquid film. In addition, occurrence of partial survival of impacting droplet is reported.

Aeroengine bearing chambers are geometrically complex, typically containing shafts, bearings, seals and stationary components. Oil is supplied for lubrication and cooling and so the chamber contains a highly rotating two-phase (oil/air) flow where the oil is typically present as droplets, ligaments, mist and films. These films may be thick or thin and film speed varies with chamber location. It is desirable to know a priori the outcome of a droplet-film impact event in terms of mass, momentum and energy transfer. There is a significant body of research on the interaction between droplets and static films. The experimental parameter space has been characterised on the basis of film thickness and impact parameter to predict the outcome of an impingement. The impingement of droplets on moving films has only begun to be investigated over the last decade and consequently models have not yet been developed and the parameter space has barely begun to be characterised. Within this paper results are presented from an experimental study in which water droplets of 3 mm and 3.8 mm at 20°C falling under the influence of gravity impinged onto water films flowing down an inclined plane. Film temperature was 30°C and film thicknesses were between 2.3 mm and 4.2 mm. High speed imaging was used to determine the impingement outcomes and cavity morphology. A high speed infrared camera was used to determine the extent of the thermally affected region and its temperature behaviour. We find that by using the resultant droplet velocity (combining droplet and film velocities) the film impingement outcomes can be characterised into regions very similar to those for static films. The data is presented as a function of splashing parameter and non-dimensional film thickness. It was observed that for these impacts on supercritical films (Fr > 1) there is less propensity for secondary droplet formation through jet breakup than on static and subcritical films (Fr < 1). Data was obtained for extent

Melt ejection is the dominant material removal mechanism in long, ms, pulse laser drilling of metals, a process with applications such as the drilling of cooling holes in turbine blades. Droplets of molten material are ejected through the entrance hole and, after breakthrough, through the exit hole. High speed filming is used to study the ejected material in order to better understand how this debris may interact with material in the immediate vicinity of the drilled hole. Existing studies have quantified various aspects of melt ejection, however they usually focus on ejection through the entrance hole. This work concentrates on rear melt ejection and is relevant to issues such as rear wall impingement. A 2kW IPG 200S fibre laser is used to drill mild steel. High speed filming is combined with image analysis to characterise the rearward-ejected material. Particle size and velocity data is presented as a function of drilling parameters. It is concluded that high speed filming combined with image analysis and proper consideration of process limitations and optimisation strategies can be a powerful tool in understanding resultant debris distributions.

The flow of a liquid film sheared by high velocity gas stream in a horizontal rectangular duct was investigated using a high-speed laser-induced fluorescence technique. Measurements of local film thickness were resolved in both longitudinal and transverse coordinates with high spatial and temporal resolution. It was found that the generation of fast and slow ripples by the disturbance waves was qualitatively the same as it was observed earlier in completely different conditions. The transverse size and curvature of the disturbance waves and ripples were measured. A relationship between the three-dimensional structure of ripples on top of disturbance waves and the two mechanisms of liquid entrainment, known as ‘bag break-up’ and ‘ligament break-up’, is proposed.

Permanent magnet synchronous generators (PMSG) are at the core of small scale wind power generators manufactured by a wide range of manufacturers in different configurations: vertical or horizontal axis blades, with various geometries and aerodynamics of the blades; by installing these small scale wind turbines in very large numbers at household levels, it is expected that these will make a positive contribution to the increase of renewable energy generation, reducing the use of fossil fuels that are blamed for climate change. However, a proper evaluation of the technical specification of these small scale wind generators in various weather conditions is necessary in order to assess the full potential of benefits. This paper reports on the implementation and testing of a power electronic dump load that allows continuously adjustable loading of a PMSG with sinusoidal currents and have the capability to self synchronize to its frequency/speed whilst avoiding transient/loosing of synchronism.

The results of an experimental study on droplet impactions in the flow of a gas-sheared liquid film are presented. In contrast to most similar studies, the impacting droplets were entrained from film surface by the gas stream. The measurements provide film thickness data, resolved in both longitudinal and transverse coordinates and in time together with the images of droplets above the interface and images of gas bubbles entrapped by liquid film. The parameters of impacting droplets were measured together with the local liquid film thickness. Two main scenarios of droplet-film interaction, based on type of film perturbation, are identified; the parameter identifying which scenario occurs is identified as the angle of impingement. At large angles an asymmetric crater appears on film surface; at shallow angles a long, narrow furrow appears. The most significant difference between the two scenarios is related to possible impact outcome: craters may lead to creation secondary droplets, whereas furrows are accompanied by entrapment of gas bubbles into the liquid film. In addition, occurrence of partial survival of impacting droplet is reported.

Melt ejection is the dominant material removal mechanism in long, ms, pulse laser drilling of metals, a process with applications such as the drilling of cooling holes in turbine blades. Droplets of molten material are ejected through the entrance hole and, after breakthrough, through the exit hole. High speed filming is used to study the ejected material in order to better understand how this debris may interact with material in the immediate vicinity of the drilled hole. Existing studies have quantified various aspects of melt ejection, however they usually focus on ejection through the entrance hole. This work concentrates on rear melt ejection and is relevant to issues such as rear wall impingement. A 2kW IPG 200S fibre laser is used to drill mild steel. High speed filming is combined with image analysis to characterise the rearward-ejected material. Particle size and velocity data is presented as a function of drilling parameters. It is concluded that high speed filming combined with image analysis and proper consideration of process limitations and optimisation strategies can be a powerful tool in understanding resultant debris distributions.

The flow of a liquid film sheared by high velocity gas stream in a horizontal rectangular duct was investigated using a high-speed laser-induced fluorescence technique. Measurements of local film thickness were resolved in both longitudinal and transverse coordinates with high spatial and temporal resolution. It was found that the generation of fast and slow ripples by the disturbance waves was qualitatively the same as it was observed earlier in completely different conditions. The transverse size and curvature of the disturbance waves and ripples were measured. A relationship between the three-dimensional structure of ripples on top of disturbance waves and the two mechanisms of liquid entrainment, known as ‘bag break-up’ and ‘ligament break-up’, is proposed.

Aeroengine bearing chambers are geometrically complex, typically containing shafts, bearings, seals and stationary components. Oil is supplied for lubrication and cooling and so the chamber contains a highly rotating two-phase (oil/air) flow where the oil is typically present as droplets, ligaments, mist and films. These films may be thick or thin and film speed varies with chamber location. It is desirable to know a priori the outcome of a droplet-film impact event in terms of mass, momentum and energy transfer. There is a significant body of research on the interaction between droplets and static films. The experimental parameter space has been characterised on the basis of film thickness and impact parameter to predict the outcome of an impingement. The impingement of droplets on moving films has only begun to be investigated over the last decade and consequently models have not yet been developed and the parameter space has barely begun to be characterised. Within this paper results are presented from an experimental study in which water droplets of 3 mm and 3.8 mm at 20°C falling under the influence of gravity impinged onto water films flowing down an inclined plane. Film temperature was 30°C and film thicknesses were between 2.3 mm and 4.2 mm. High speed imaging was used to determine the impingement outcomes and cavity morphology. A high speed infrared camera was used to determine the extent of the thermally affected region and its temperature behaviour. We find that by using the resultant droplet velocity (combining droplet and film velocities) the film impingement outcomes can be characterised into regions very similar to those for static films. The data is presented as a function of splashing parameter and non-dimensional film thickness. It was observed that for these impacts on supercritical films (Fr > 1) there is less propensity for secondary droplet formation through jet breakup than on static and subcritical films (Fr < 1). Data was obtained for extent

Permanent magnet synchronous generators (PMSG) are at the core of small scale wind power generators manufactured by a wide range of manufacturers in different configurations: vertical or horizontal axis blades, with various geometries and aerodynamics of the blades; by installing these small scale wind turbines in very large numbers at household levels, it is expected that these will make a positive contribution to the increase of renewable energy generation, reducing the use of fossil fuels that are blamed for climate change. However, a proper evaluation of the technical specification of these small scale wind generators in various weather conditions is necessary in order to assess the full potential of benefits. This paper reports on the implementation and testing of a power electronic dump load that allows continuously adjustable loading of a PMSG with sinusoidal currents and have the capability to self synchronize to its frequency/speed whilst avoiding transient/loosing of synchronism.