FLUIDS - Enginyeria de Fluids
http://hdl.handle.net/2117/3251
2017-10-24T11:33:36ZComputational fluid dynamics modeling of impinging gas-jet systems: II. Application to an industrial cooling system device
http://hdl.handle.net/2117/108584
Computational fluid dynamics modeling of impinging gas-jet systems: II. Application to an industrial cooling system device
Coussirat Núñez, Miguel Gustavo; van Beeck, J; Mestres Ridge, Marc; Egusquiza Estévez, Eduard; Buchlin, J-M; Valero Ferrando, Ma. del Carmen
A numerical analysis of the flow behavior in industrial cooling systems based on arrays of impinging jets has been performed, using several eddy viscosity models to determine their modeling capabilities. For the cooling system studied, and in terms of mean Nusselt number values, the best agreement between experimental results and numerical predictions was obtained with the realizable k-e model. On the other hand, numerical predictions of the local Nusselt number and its spatial variations along the wall are better adjusted to the experiments when using either the standard k-e or the standard k-¿ models. The results obtained also show that the predicted thermal field depends strongly on the combination of near-wall treatment and selected turbulence model.
2017-10-10T10:43:35ZCoussirat Núñez, Miguel Gustavovan Beeck, JMestres Ridge, MarcEgusquiza Estévez, EduardBuchlin, J-MValero Ferrando, Ma. del CarmenA numerical analysis of the flow behavior in industrial cooling systems based on arrays of impinging jets has been performed, using several eddy viscosity models to determine their modeling capabilities. For the cooling system studied, and in terms of mean Nusselt number values, the best agreement between experimental results and numerical predictions was obtained with the realizable k-e model. On the other hand, numerical predictions of the local Nusselt number and its spatial variations along the wall are better adjusted to the experiments when using either the standard k-e or the standard k-¿ models. The results obtained also show that the predicted thermal field depends strongly on the combination of near-wall treatment and selected turbulence model.Computational fluid dynamics modeling of impinging gas-jet systems: I. Assessment of eddy viscosity models
http://hdl.handle.net/2117/108427
Computational fluid dynamics modeling of impinging gas-jet systems: I. Assessment of eddy viscosity models
Coussirat Núñez, Miguel Gustavo; van Beeck, J; Mestres Ridge, Marc; Egusquiza Estévez, Eduard; Buchlin, J-M; Escaler Puigoriol, Francesc Xavier
Computational fluid dynamics plays an important role in engineering design. To gain insight into solving problems involving complex industrial flows, such as impinging gas-jet systems (IJS), an evaluation of several eddy viscosity models, applied to these IJS has been made. Good agreement with experimental mean values for the field velocities and Nusselt number was obtained, but velocity fluctuations and local values of Nusselt number along the wall disagree with the experiments in some cases. Experiments show a clear relation between the nozzle-to-plate distance and the Nusselt number at the stagnation point. Those trends were only reproduced by some of the numerical experiments. The conclusions of this study are useful in the field of heat transfer predictions in industrial IJS devices, and therefore for its design.
2017-10-06T08:09:14ZCoussirat Núñez, Miguel Gustavovan Beeck, JMestres Ridge, MarcEgusquiza Estévez, EduardBuchlin, J-MEscaler Puigoriol, Francesc XavierComputational fluid dynamics plays an important role in engineering design. To gain insight into solving problems involving complex industrial flows, such as impinging gas-jet systems (IJS), an evaluation of several eddy viscosity models, applied to these IJS has been made. Good agreement with experimental mean values for the field velocities and Nusselt number was obtained, but velocity fluctuations and local values of Nusselt number along the wall disagree with the experiments in some cases. Experiments show a clear relation between the nozzle-to-plate distance and the Nusselt number at the stagnation point. Those trends were only reproduced by some of the numerical experiments. The conclusions of this study are useful in the field of heat transfer predictions in industrial IJS devices, and therefore for its design.Accurate determination of the frequency response function of submerged and confined structures by using PZT-patches
http://hdl.handle.net/2117/104530
Accurate determination of the frequency response function of submerged and confined structures by using PZT-patches
Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Bossio, Matias
To accurately determine the dynamic response of a structure is of relevant interest in many engineering applications. Particularly, it is of paramount importance to determine the Frequency Response Function (FRF) for structures subjected to dynamic loads in order to avoid resonance and fatigue problems that can drastically reduce their useful life. One challenging case is the experimental determination of the FRF of submerged and confined structures, such as hydraulic turbines, which are greatly affected by dynamic problems as reported in many cases in the past. The utilization of classical and calibrated exciters such as instrumented hammers or shakers to determine the FRF in such structures can be very complex due to the confinement of the structure and because their use can disturb the boundary conditions affecting the experimental results. For such cases, Piezoelectric Patches (PZTs), which are very light, thin and small, could be a very good option. Nevertheless, the main drawback of these exciters is that the calibration as dynamic force transducers (relationship voltage/force) has not been successfully obtained in the past. Therefore, in this paper, a method to accurately determine the FRF of submerged and confined structures by using PZTs is developed and validated. The method consists of experimentally determining some characteristic parameters that define the FRF, with an uncalibrated PZT exciting the structure. These parameters, which have been experimentally determined, are then introduced in a validated numerical model of the tested structure. In this way, the FRF of the structure can be estimated with good accuracy. With respect to previous studies, where only the natural frequencies and mode shapes were considered, this paper discuss and experimentally proves the best excitation characteristic to obtain also the damping ratios and proposes a procedure to fully determine the FRF. The method proposed here has been validated for the structure vibrating in air comparing the FRF experimentally obtained with a calibrated exciter (impact Hammer) and the FRF obtained with the described method. Finally, the same methodology has been applied for the structure submerged and close to a rigid wall, where it is extremely important to not modify the boundary conditions for an accurate determination of the FRF. As experimentally shown in this paper, in such cases, the use of PZTs combined with the proposed methodology gives much more accurate estimations of the FRF than other calibrated exciters typically used for the same purpose. Therefore, the validated methodology proposed in this paper can be used to obtain the FRF of a generic submerged and confined structure, without a previous calibration of the PZT.
2017-05-17T07:25:25ZPresas Batlló, AlexandreValentín Ruiz, DavidEgusquiza Estévez, EduardValero Ferrando, Ma. del CarmenEgusquiza Montagut, MònicaBossio, MatiasTo accurately determine the dynamic response of a structure is of relevant interest in many engineering applications. Particularly, it is of paramount importance to determine the Frequency Response Function (FRF) for structures subjected to dynamic loads in order to avoid resonance and fatigue problems that can drastically reduce their useful life. One challenging case is the experimental determination of the FRF of submerged and confined structures, such as hydraulic turbines, which are greatly affected by dynamic problems as reported in many cases in the past. The utilization of classical and calibrated exciters such as instrumented hammers or shakers to determine the FRF in such structures can be very complex due to the confinement of the structure and because their use can disturb the boundary conditions affecting the experimental results. For such cases, Piezoelectric Patches (PZTs), which are very light, thin and small, could be a very good option. Nevertheless, the main drawback of these exciters is that the calibration as dynamic force transducers (relationship voltage/force) has not been successfully obtained in the past. Therefore, in this paper, a method to accurately determine the FRF of submerged and confined structures by using PZTs is developed and validated. The method consists of experimentally determining some characteristic parameters that define the FRF, with an uncalibrated PZT exciting the structure. These parameters, which have been experimentally determined, are then introduced in a validated numerical model of the tested structure. In this way, the FRF of the structure can be estimated with good accuracy. With respect to previous studies, where only the natural frequencies and mode shapes were considered, this paper discuss and experimentally proves the best excitation characteristic to obtain also the damping ratios and proposes a procedure to fully determine the FRF. The method proposed here has been validated for the structure vibrating in air comparing the FRF experimentally obtained with a calibrated exciter (impact Hammer) and the FRF obtained with the described method. Finally, the same methodology has been applied for the structure submerged and close to a rigid wall, where it is extremely important to not modify the boundary conditions for an accurate determination of the FRF. As experimentally shown in this paper, in such cases, the use of PZTs combined with the proposed methodology gives much more accurate estimations of the FRF than other calibrated exciters typically used for the same purpose. Therefore, the validated methodology proposed in this paper can be used to obtain the FRF of a generic submerged and confined structure, without a previous calibration of the PZT.Study of available turbulence and cavitation models to reproduce flow patterns in confined flows
http://hdl.handle.net/2117/104062
Study of available turbulence and cavitation models to reproduce flow patterns in confined flows
Coussirat Núñez, Miguel Gustavo; Moll, Flavio; Cappa, E. Franco; Fontanals García, Alfred
Cavitating flow in nozzles is a complex flow which implies a highly turbulent two-phase
one. An accurate simulation which improves some numerical results found in the literature was achieved by means of an extensive analysis of the capabilities of several numerical models for turbulence and cavitation. The analysis performed involves calibration/
optimization tasks based on the physics of this kind of flow. This work aims to provide a quantitative criterion for the judgment of internal flow state, because it was demonstrated that the numerical results obtained with noncalibrated models could be enhanced by means of a careful calibration and thus saving computational costs.
2017-05-04T11:55:17ZCoussirat Núñez, Miguel GustavoMoll, FlavioCappa, E. FrancoFontanals García, AlfredCavitating flow in nozzles is a complex flow which implies a highly turbulent two-phase
one. An accurate simulation which improves some numerical results found in the literature was achieved by means of an extensive analysis of the capabilities of several numerical models for turbulence and cavitation. The analysis performed involves calibration/
optimization tasks based on the physics of this kind of flow. This work aims to provide a quantitative criterion for the judgment of internal flow state, because it was demonstrated that the numerical results obtained with noncalibrated models could be enhanced by means of a careful calibration and thus saving computational costs.Experimental study of a vibrating disk submerged in a fluid-filled tank and confined with a nonrigid cover
http://hdl.handle.net/2117/102117
Experimental study of a vibrating disk submerged in a fluid-filled tank and confined with a nonrigid cover
Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica
Determining the dynamic response of submerged and confined disklike structures is of interest in engineering applications, such as in hydraulic turbine runners. This dynamic response is heavily affected by the added mass and damping as well as the proximity of solid boundaries. These solid boundaries are normally considered as completely rigid in theoretical or numerical calculations, however, this assumption is not always valid. Some hydraulic turbines have noncompletely stiff casings, which can modify the dynamic response of the runner itself, affecting specially its natural frequencies and damping behavior. To determine the influence of noncompletely rigid nearby surfaces in the dynamic behavior of a submerged structure, an experimental test rig has been constructed. This test rig is based on a disk attached to a shaft and confined in a tank covered with two different casings with different mass and stiffness. For both covers and different disk to cover distances, natural frequencies and damping ratios of the disk have been obtained experimentally. Accelerometers installed on the disk and covers as well as pressure sensors are used for this purpose. Results obtained for all the cases are discussed in detail and compared with a simplified theoretical model.
2017-03-08T10:58:24ZValentín Ruiz, DavidPresas Batlló, AlexandreEgusquiza Estévez, EduardValero Ferrando, Ma. del CarmenEgusquiza Montagut, MònicaDetermining the dynamic response of submerged and confined disklike structures is of interest in engineering applications, such as in hydraulic turbine runners. This dynamic response is heavily affected by the added mass and damping as well as the proximity of solid boundaries. These solid boundaries are normally considered as completely rigid in theoretical or numerical calculations, however, this assumption is not always valid. Some hydraulic turbines have noncompletely stiff casings, which can modify the dynamic response of the runner itself, affecting specially its natural frequencies and damping behavior. To determine the influence of noncompletely rigid nearby surfaces in the dynamic behavior of a submerged structure, an experimental test rig has been constructed. This test rig is based on a disk attached to a shaft and confined in a tank covered with two different casings with different mass and stiffness. For both covers and different disk to cover distances, natural frequencies and damping ratios of the disk have been obtained experimentally. Accelerometers installed on the disk and covers as well as pressure sensors are used for this purpose. Results obtained for all the cases are discussed in detail and compared with a simplified theoretical model.Influence of the boundary conditions on the natural frequencies of a Francis turbine
http://hdl.handle.net/2117/102049
Influence of the boundary conditions on the natural frequencies of a Francis turbine
Valentín Ruiz, David; Ramos Martín, David; Bossio, Matias; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen
Natural frequencies estimation of Francis turbines is of paramount importance in the stage of design in order to avoid vibration and resonance problems especially during transient events. Francis turbine runners are submerged in water and confined with small axial and radial gaps which considerably decrease their natural frequencies in comparison to the same structure in the air. Acoustic-structural FSI simulations have been used to evaluate the influence of these gaps. This model considers an entire prototype of a Francis turbine, including generator, shaft,
runner and surrounding water. The radial gap between the runner and the static parts has been changed from the real configuration (about 0.04% the runner diameter) to 1% of the runner diameter to evaluate its influence on the machine natural frequencies. Mode-shapes and natural frequencies of the whole machine are discussed for all the boundary conditions tested
2017-03-07T13:26:58ZValentín Ruiz, DavidRamos Martín, DavidBossio, MatiasPresas Batlló, AlexandreEgusquiza Estévez, EduardValero Ferrando, Ma. del CarmenNatural frequencies estimation of Francis turbines is of paramount importance in the stage of design in order to avoid vibration and resonance problems especially during transient events. Francis turbine runners are submerged in water and confined with small axial and radial gaps which considerably decrease their natural frequencies in comparison to the same structure in the air. Acoustic-structural FSI simulations have been used to evaluate the influence of these gaps. This model considers an entire prototype of a Francis turbine, including generator, shaft,
runner and surrounding water. The radial gap between the runner and the static parts has been changed from the real configuration (about 0.04% the runner diameter) to 1% of the runner diameter to evaluate its influence on the machine natural frequencies. Mode-shapes and natural frequencies of the whole machine are discussed for all the boundary conditions testedDynamic response of a rotating disk submerged and confined. Influence of the axial gap
http://hdl.handle.net/2117/87181
Dynamic response of a rotating disk submerged and confined. Influence of the axial gap
Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Seidel, Ulrich
In this paper, the natural frequencies and mode shapes of a rotating disk submerged and totally confined inside a rigid casing, have been obtained. These have been calculated analytically, numerically and experimentally for different axial gaps disk-casing. A simplified analytical model to analyse the dynamic response of a rotating disk submerged and confined, that has been used and validated in previous researches, is used in this case, generalised for arbitrary axial gaps disk-casing. To use this model, it is necessary to know the averaged rotating speed of the flow with respect to the disk. This parameter is obtained after an analytical discussion of the motion of the flow inside the casing where the disk rotates, and by means of CFD simulations for different axial positions of the disk. The natural frequencies of the rotating disk for the different axial confinements can be calculated following this method. A Finite Element Model has been built up to obtain the natural frequencies by means of computational simulation. The relative velocity of the flow with respect to the disk is also introduced in the simulation model in order to estimate the natural frequencies of the rotating disk. Experimental tests have been performed with a rotating disk test rig. A thin stainless steel disk (thickness of 8 mm, (h/r<5%) and mass of 7.6 kg) rotates inside a rigid casing. The position of the disk can be adjusted at several axial gaps disk-casing. A piezoelectric patch (PZT) attached on the rotating disk is used to excite the structure. Several miniature and submergible accelerometers have measured the response from the rotating frame. Excitation and measured signals are transmitted from the rotating to the stationary frame through a slip ring system. Experimental results are contrasted with the results obtained by the analytical and numerical model. Thereby, the influence of the axial gap disk-casing on the natural frequencies of a rotating disk totally confined and surrounded by a heavy fluid is determined.
2016-05-19T10:37:15ZPresas Batlló, AlexandreValentín Ruiz, DavidEgusquiza Estévez, EduardValero Ferrando, Ma. del CarmenSeidel, UlrichIn this paper, the natural frequencies and mode shapes of a rotating disk submerged and totally confined inside a rigid casing, have been obtained. These have been calculated analytically, numerically and experimentally for different axial gaps disk-casing. A simplified analytical model to analyse the dynamic response of a rotating disk submerged and confined, that has been used and validated in previous researches, is used in this case, generalised for arbitrary axial gaps disk-casing. To use this model, it is necessary to know the averaged rotating speed of the flow with respect to the disk. This parameter is obtained after an analytical discussion of the motion of the flow inside the casing where the disk rotates, and by means of CFD simulations for different axial positions of the disk. The natural frequencies of the rotating disk for the different axial confinements can be calculated following this method. A Finite Element Model has been built up to obtain the natural frequencies by means of computational simulation. The relative velocity of the flow with respect to the disk is also introduced in the simulation model in order to estimate the natural frequencies of the rotating disk. Experimental tests have been performed with a rotating disk test rig. A thin stainless steel disk (thickness of 8 mm, (h/r<5%) and mass of 7.6 kg) rotates inside a rigid casing. The position of the disk can be adjusted at several axial gaps disk-casing. A piezoelectric patch (PZT) attached on the rotating disk is used to excite the structure. Several miniature and submergible accelerometers have measured the response from the rotating frame. Excitation and measured signals are transmitted from the rotating to the stationary frame through a slip ring system. Experimental results are contrasted with the results obtained by the analytical and numerical model. Thereby, the influence of the axial gap disk-casing on the natural frequencies of a rotating disk totally confined and surrounded by a heavy fluid is determined.Monitoring of rotor-stator interaction in pump-turbine using vibrations mesured with on-board sensors rotating with shaft
http://hdl.handle.net/2117/87178
Monitoring of rotor-stator interaction in pump-turbine using vibrations mesured with on-board sensors rotating with shaft
Rodriguez Godoy, Cristian; Mateos Prieto, Borja; Egusquiza Estévez, Eduard
Current trends in design of pump-turbines have led into higher rotor-stator interaction (RSI) loads over impeller-runner. These dynamic loads are of special interest having produced catastrophic failures in pump-turbines. Determining RSI characteristics facilitates the proposal of actions that will prevent these failures. Pressure measurements all around the perimeter of the impeller-runner are appropriate to monitor and detect RSI characteristics. Unfortunately most installed pump-turbines are not manufactured with in-built pressure sensors in appropriate positions to monitor RSI. For this reason, vibration measurements are the preferred method to monitor RSI in industry. Usually vibrations are measured in two perpendicular radial directions in bearings where valuable information could be lost due to bearing response. In this work, in order to avoid the effect of bearing response on measurement, two vibration sensors are installed rotating with the shaft. The RSI characteristics obtained with pressure measurements were compared to those determined using vibration measurements. The RSI characteristics obtained with pressure measurements were also determined using vibrations measured rotating with shaft. These RSI characteristics were not possible to be determined using the vibrations measured in guide bearing. Finally, it is recommended to measure vibrations rotating with shaft to detect RSI characteristics in installed pump-turbines as a more practical and reliable method to monitor RSI characteristics.
2016-05-19T09:18:40ZRodriguez Godoy, CristianMateos Prieto, BorjaEgusquiza Estévez, EduardCurrent trends in design of pump-turbines have led into higher rotor-stator interaction (RSI) loads over impeller-runner. These dynamic loads are of special interest having produced catastrophic failures in pump-turbines. Determining RSI characteristics facilitates the proposal of actions that will prevent these failures. Pressure measurements all around the perimeter of the impeller-runner are appropriate to monitor and detect RSI characteristics. Unfortunately most installed pump-turbines are not manufactured with in-built pressure sensors in appropriate positions to monitor RSI. For this reason, vibration measurements are the preferred method to monitor RSI in industry. Usually vibrations are measured in two perpendicular radial directions in bearings where valuable information could be lost due to bearing response. In this work, in order to avoid the effect of bearing response on measurement, two vibration sensors are installed rotating with the shaft. The RSI characteristics obtained with pressure measurements were compared to those determined using vibration measurements. The RSI characteristics obtained with pressure measurements were also determined using vibrations measured rotating with shaft. These RSI characteristics were not possible to be determined using the vibrations measured in guide bearing. Finally, it is recommended to measure vibrations rotating with shaft to detect RSI characteristics in installed pump-turbines as a more practical and reliable method to monitor RSI characteristics.On the capability of structural–acoustical fluid–structure interaction simulations to predict natural frequencies of rotating disklike structures submerged in a heavy fluid
http://hdl.handle.net/2117/86669
On the capability of structural–acoustical fluid–structure interaction simulations to predict natural frequencies of rotating disklike structures submerged in a heavy fluid
Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen
Predicting natural frequencies of rotating disklike structures submerged in water is of paramount importance in the field of hydraulic machinery, since the dynamic response of disks presents similarities to the dynamic response of pump-turbine runners. Well-known computational methods, such as structural-acoustical fluid–structure interaction (FSI) simulations, are perfectly capable to predict the added mass effects of standing submerged disks. However, the capability of these simulations to predict the effect of rotation in the natural frequencies of submerged disks has not been investigated. To obtain adequate results, the relationship between the disk rotation and the fluid rotation has to be introduced in the simulation model to consider the effects of the surrounding flow and the transmission within rotating and stationary frame. This procedure is explained and discussed in this technical brief comparing analytical, numerical, and experimental results.
2016-05-06T07:42:40ZValentín Ruiz, DavidPresas Batlló, AlexandreEgusquiza Estévez, EduardValero Ferrando, Ma. del CarmenPredicting natural frequencies of rotating disklike structures submerged in water is of paramount importance in the field of hydraulic machinery, since the dynamic response of disks presents similarities to the dynamic response of pump-turbine runners. Well-known computational methods, such as structural-acoustical fluid–structure interaction (FSI) simulations, are perfectly capable to predict the added mass effects of standing submerged disks. However, the capability of these simulations to predict the effect of rotation in the natural frequencies of submerged disks has not been investigated. To obtain adequate results, the relationship between the disk rotation and the fluid rotation has to be introduced in the simulation model to consider the effects of the surrounding flow and the transmission within rotating and stationary frame. This procedure is explained and discussed in this technical brief comparing analytical, numerical, and experimental results.Assessment of the economic and environmental impact of double glazed façade ventilation systems in Mediterranean climates
http://hdl.handle.net/2117/86618
Assessment of the economic and environmental impact of double glazed façade ventilation systems in Mediterranean climates
Valentín Ruiz, David; Guardo Zabaleta, Alfredo de Jesús; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Alavedra, Pere
Free convection is the most often used method in order to reduce solar load gains on a building with double glazed façades (DGFs). However, depending on the climate factors, the thermal performance of a DGF may not be satisfactory and extra energy costs are required to obtain suitable comfort conditions inside the building. Forced ventilation systems are a feasible alternative to improve the thermal performance of a DGF in Mediterranean climates where large solar gains are a permanent condition throughout the year. In this paper the feasibility of using diverse forced ventilation methods in DGF is evaluated. In addition, an economical comparison between different mechanical ventilation systems was performed in order to demonstrate the viability of DGF forced ventilation. Moreover, an environmental study was carried out to prove the positive energetic balance on cooling loads between free and forced convection in DGF for Mediterranean climates. For this investigation, a CFD model was used to simulate the thermal conditions in a DGF for the different ventilation systems. Results obtained for heat flux, temperature and reductions in solar load gains were analyzed and applied for the economic and environmental research.
2016-05-05T08:01:34ZValentín Ruiz, DavidGuardo Zabaleta, Alfredo de JesúsEgusquiza Estévez, EduardValero Ferrando, Ma. del CarmenAlavedra, PereFree convection is the most often used method in order to reduce solar load gains on a building with double glazed façades (DGFs). However, depending on the climate factors, the thermal performance of a DGF may not be satisfactory and extra energy costs are required to obtain suitable comfort conditions inside the building. Forced ventilation systems are a feasible alternative to improve the thermal performance of a DGF in Mediterranean climates where large solar gains are a permanent condition throughout the year. In this paper the feasibility of using diverse forced ventilation methods in DGF is evaluated. In addition, an economical comparison between different mechanical ventilation systems was performed in order to demonstrate the viability of DGF forced ventilation. Moreover, an environmental study was carried out to prove the positive energetic balance on cooling loads between free and forced convection in DGF for Mediterranean climates. For this investigation, a CFD model was used to simulate the thermal conditions in a DGF for the different ventilation systems. Results obtained for heat flux, temperature and reductions in solar load gains were analyzed and applied for the economic and environmental research.