Abstract This paper presents the numerical analysis of a convergent-divergent circular nozzle with the exit Mach number of 1.69 with and without passive control at the exit. The passive control method opted for this analysis was inward and outward ascending triangular protrusion. This paper explores the influence of the passive control geometry and its blockage area concerning the nozzle exit. The nozzle pressure ratio (NPR) used for carrying out the flow analysis were 3, 4.932, and 6. Two different inward and outward protrusions were used with a height of 1.5 mm and 3 mm. From the results, the potential core length of the protrusion 1.5 mm height was not much changed in the both outward and inward cases. But when the height of the protrusion was increased to 3 mm, there was a noticeable core length reduction at all NPR but with different cases. At the NPR of 6, the potential core length of the inward protrusions 3 mm was reduced by 44 % compared to the plain CD nozzle.
{"title":"Numerical analysis on the effect of passive control geometry in supersonic jet mixing enhancement","authors":"N. Subramani, S. M, Gowtham Gajapathy","doi":"10.1515/tjj-2023-0068","DOIUrl":"https://doi.org/10.1515/tjj-2023-0068","url":null,"abstract":"Abstract This paper presents the numerical analysis of a convergent-divergent circular nozzle with the exit Mach number of 1.69 with and without passive control at the exit. The passive control method opted for this analysis was inward and outward ascending triangular protrusion. This paper explores the influence of the passive control geometry and its blockage area concerning the nozzle exit. The nozzle pressure ratio (NPR) used for carrying out the flow analysis were 3, 4.932, and 6. Two different inward and outward protrusions were used with a height of 1.5 mm and 3 mm. From the results, the potential core length of the protrusion 1.5 mm height was not much changed in the both outward and inward cases. But when the height of the protrusion was increased to 3 mm, there was a noticeable core length reduction at all NPR but with different cases. At the NPR of 6, the potential core length of the inward protrusions 3 mm was reduced by 44 % compared to the plain CD nozzle.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48515732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Jeyakumar, Akash Shrikant Patale, Prince Sharma
Abstract The flow performance of a dual wall-mounted cavity in a strut-injector scramjet combustor in steady reacting flow conditions is computationally analyzed. A baseline configuration corresponding to DLR experiments and two proposed configurations with varying bottom wall cavity depth and fixed top wall ramp is considered. Steady-flow computations are performed using the 2-D Reynolds Averaged Navier–Stokes method with k-ω SST turbulence closure coupled and single-step reaction chemistry. The calculated flow patterns, density, pressure, and temperature fields are compared with shadowgraph and wall pressure measurements from DLR experiments. The cavity and strut are mounted downstream of the strut to analyze the shock patterns and their interference with the shear layer mixing features. The estimated flow patterns, density, pressure, and temperature fields are compared with shadowgraph and wall pressure measurements from DLR experiments. Incorporating cavity and ramp configuration provides earlier complete combustion compared to the baseline model, with a marginal rise in the total pressure caused by additional shock wave formation that emanates from the corners of the cavity and ramp. The combustion zone widens in the lateral direction as the cavity shifts the shock train downstream of the strut injector owing to intense shock shear layer interactions.
{"title":"Impact of cavity and ramp configuration on the combustion performance of a strut-based scramjet combustor","authors":"S. Jeyakumar, Akash Shrikant Patale, Prince Sharma","doi":"10.1515/tjj-2023-0067","DOIUrl":"https://doi.org/10.1515/tjj-2023-0067","url":null,"abstract":"Abstract The flow performance of a dual wall-mounted cavity in a strut-injector scramjet combustor in steady reacting flow conditions is computationally analyzed. A baseline configuration corresponding to DLR experiments and two proposed configurations with varying bottom wall cavity depth and fixed top wall ramp is considered. Steady-flow computations are performed using the 2-D Reynolds Averaged Navier–Stokes method with k-ω SST turbulence closure coupled and single-step reaction chemistry. The calculated flow patterns, density, pressure, and temperature fields are compared with shadowgraph and wall pressure measurements from DLR experiments. The cavity and strut are mounted downstream of the strut to analyze the shock patterns and their interference with the shear layer mixing features. The estimated flow patterns, density, pressure, and temperature fields are compared with shadowgraph and wall pressure measurements from DLR experiments. Incorporating cavity and ramp configuration provides earlier complete combustion compared to the baseline model, with a marginal rise in the total pressure caused by additional shock wave formation that emanates from the corners of the cavity and ramp. The combustion zone widens in the lateral direction as the cavity shifts the shock train downstream of the strut injector owing to intense shock shear layer interactions.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49542980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Understanding the occurrence of various feedback mechanisms of an under-expanded impinging supersonic jet is a crucial task in research. The presence of several jet modes is examined in this study for the flat and corrugated impinging plate geometries. The behavior of impinging plate configurations during mode switching is investigated by varying the flow state, such as the jet Mach number. The staging behavior at various jet Mach numbers is observed using acoustic spectral plots and schlieren flow visualization. To explore the presence of various types of modes during the jet impingement due to the modification of jet Mach number, ensemble averaging and Proper Orthogonal Decomposition of schlieren images are carried out. In the majority of situations, the corrugated design shows a reduction in tonal noise and overall sound pressure level. In exceptional cases, for the corrugated plates, the enhanced overall sound pressure level is caused by the existence of axisymmetric instability (A1, A2).
{"title":"Proper Orthogonal Decomposition analysis of mode switching in supersonic jets impinging on flat and corrugated plates","authors":"D. Sarangi, Ramanujam Karthik, K. Srinivasan","doi":"10.1515/tjj-2023-0071","DOIUrl":"https://doi.org/10.1515/tjj-2023-0071","url":null,"abstract":"Abstract Understanding the occurrence of various feedback mechanisms of an under-expanded impinging supersonic jet is a crucial task in research. The presence of several jet modes is examined in this study for the flat and corrugated impinging plate geometries. The behavior of impinging plate configurations during mode switching is investigated by varying the flow state, such as the jet Mach number. The staging behavior at various jet Mach numbers is observed using acoustic spectral plots and schlieren flow visualization. To explore the presence of various types of modes during the jet impingement due to the modification of jet Mach number, ensemble averaging and Proper Orthogonal Decomposition of schlieren images are carried out. In the majority of situations, the corrugated design shows a reduction in tonal noise and overall sound pressure level. In exceptional cases, for the corrugated plates, the enhanced overall sound pressure level is caused by the existence of axisymmetric instability (A1, A2).","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44904841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In variable geometry turbine vanes, tip clearance height and shape vary with the rotation of the vane, which affect the aerodynamic performance significantly. However, these issues are rarely considered in published studies. The current paper investigated the flow field features of transonic variable geometry turbine vanes with non-uniform partial clearance induced by the vane rotating. The results show that: The influence of guide vane rotation on the clearance height and its distribution cannot be ignored. At the same turning angle, the maximum clearance difference is up to 0.79 mm (0.8 % vane height). The height and shape variation of the non-uniform clearance leads to the change in the leakage flow rate, secondary flow structure, and aerodynamic loss of the variable guide vane. Under the combined effect of pressure difference on both sides of the clearance, axial and circumferential non-uniformity of clearance height, the total pressure loss coefficient is up to 9.44 % when the turning angle is −10°. The effect of the pivot on the clearance flow was also analyzed. The pivot increases the pressure in the gap flow field and reduces leakage flow velocity. However, a backflow region appears at the suction side of the pivot, which increases the aerodynamic losses.
{"title":"Numerical investigation of tip clearance flow in a variable geometry turbine with non-uniform partial clearance","authors":"Yueqi Liu, Shaowen Chen, S. Wang","doi":"10.1515/tjj-2023-0063","DOIUrl":"https://doi.org/10.1515/tjj-2023-0063","url":null,"abstract":"Abstract In variable geometry turbine vanes, tip clearance height and shape vary with the rotation of the vane, which affect the aerodynamic performance significantly. However, these issues are rarely considered in published studies. The current paper investigated the flow field features of transonic variable geometry turbine vanes with non-uniform partial clearance induced by the vane rotating. The results show that: The influence of guide vane rotation on the clearance height and its distribution cannot be ignored. At the same turning angle, the maximum clearance difference is up to 0.79 mm (0.8 % vane height). The height and shape variation of the non-uniform clearance leads to the change in the leakage flow rate, secondary flow structure, and aerodynamic loss of the variable guide vane. Under the combined effect of pressure difference on both sides of the clearance, axial and circumferential non-uniformity of clearance height, the total pressure loss coefficient is up to 9.44 % when the turning angle is −10°. The effect of the pivot on the clearance flow was also analyzed. The pivot increases the pressure in the gap flow field and reduces leakage flow velocity. However, a backflow region appears at the suction side of the pivot, which increases the aerodynamic losses.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46637710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Aero engine performance analysis is very important for engines under development as well as for engines in service for condition monitoring. Predictions of aero engine performance and ability of building the simulation model is an invaluable asset for designers, manufacturer and end-use operator. This paper presents the methodology in establishing the baseline performance of a twin spool mixed flow low bypass turbofan engine through extensive testing at engine test bench. The baseline data is used to validate a GasTurb model which is subsequently used for assessment of off-design performance and component degradation responsible for performance deterioration at various service hours. The estimated exhaust gas temperatures by the model for degraded engines are in good agreement with the measured data. The model further assesses the drop in HP compressor efficiency and shift in operating line which will be very useful for taking judicious decision for withdrawal of engines and is expected to reduce or delay withdrawals and increase the availability of engines at operating base.
{"title":"Assessment of performance degradation of a mixed flow low bypass turbofan engine through GasTurb simulation","authors":"Narahari Rath, Mishra R. K., A. Kushari","doi":"10.1515/tjj-2023-0064","DOIUrl":"https://doi.org/10.1515/tjj-2023-0064","url":null,"abstract":"Abstract Aero engine performance analysis is very important for engines under development as well as for engines in service for condition monitoring. Predictions of aero engine performance and ability of building the simulation model is an invaluable asset for designers, manufacturer and end-use operator. This paper presents the methodology in establishing the baseline performance of a twin spool mixed flow low bypass turbofan engine through extensive testing at engine test bench. The baseline data is used to validate a GasTurb model which is subsequently used for assessment of off-design performance and component degradation responsible for performance deterioration at various service hours. The estimated exhaust gas temperatures by the model for degraded engines are in good agreement with the measured data. The model further assesses the drop in HP compressor efficiency and shift in operating line which will be very useful for taking judicious decision for withdrawal of engines and is expected to reduce or delay withdrawals and increase the availability of engines at operating base.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46638670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In this study, the authors propose an optimization process to design the baseline rotor of a supersonic through-flow fan (STFF) at an inlet Mach number of 2.0 based on Genetic Algorithm. Unlike the improvement in performance brought about by the pre-compression of conventional supersonic profiles in the presence of axial pressure flow, pre-compression did not help improve the performance of the rotor of the STFF. The efficiency of elements of the blade at spanwise heights of 10 %, 50 %, and 90 % increased by 2.47 %, 1.95 %, and 2.49 %, respectively. The performance of the rotor of the STFF that was reconstructed by stacking the optimized elements of the blade was improved at the design point as well as in off-design conditions by using three-dimensional computational fluid dynamics (CFD) simulations. The performance of the blade also improved considerably, with increases of by 2.46 % and 9.59 % in its isentropic efficiency and the overall pressure ratio, respectively.
{"title":"Design optimization of a supersonic through-flow fan rotor based on the blade profiles","authors":"Jutao Yang, L. Ji, Yuxin Shen, Lingchen Zhou","doi":"10.1515/tjj-2022-0082","DOIUrl":"https://doi.org/10.1515/tjj-2022-0082","url":null,"abstract":"Abstract In this study, the authors propose an optimization process to design the baseline rotor of a supersonic through-flow fan (STFF) at an inlet Mach number of 2.0 based on Genetic Algorithm. Unlike the improvement in performance brought about by the pre-compression of conventional supersonic profiles in the presence of axial pressure flow, pre-compression did not help improve the performance of the rotor of the STFF. The efficiency of elements of the blade at spanwise heights of 10 %, 50 %, and 90 % increased by 2.47 %, 1.95 %, and 2.49 %, respectively. The performance of the rotor of the STFF that was reconstructed by stacking the optimized elements of the blade was improved at the design point as well as in off-design conditions by using three-dimensional computational fluid dynamics (CFD) simulations. The performance of the blade also improved considerably, with increases of by 2.46 % and 9.59 % in its isentropic efficiency and the overall pressure ratio, respectively.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46558494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jutao Yang, Yuxin Shen, L. Ji, Jiabin Li, Lingchen Zhou
Abstract This article delves into the intricate relationship between the modeling parameters of an axial supersonic through-flow fan (STFF) rotor and its performance based on an active subspace method. It considers the influence of the STFF rotor key parameters on its performance. Implementing the active subspace method generates cloud maps to visualize the performance of the STFF rotor. Moreover, this study investigates the correlation between Bezier curve variables for constructing blade angles and critical performance metrics, such as the total pressure ratio and isentropic efficiency. After a 50 % chord length, the Bezier control point parameters dominate the effect on the total pressure ratio with a linear relationship. This article provides comparative flow field analyses on the blade elements with different performances under three working conditions. Under the constraint of the blade chamber turning angle, there is a linear relationship between the upper and lower limits of the isentropic efficiency distribution and total pressure ratio. This study shows that the total pressure ratio, installation angle, and maximum deflection value are positively associated. Further analysis provides an empirical formula.
{"title":"Active subspace-based performance analysis of supersonic through-flow fan rotor","authors":"Jutao Yang, Yuxin Shen, L. Ji, Jiabin Li, Lingchen Zhou","doi":"10.1515/tjj-2023-0044","DOIUrl":"https://doi.org/10.1515/tjj-2023-0044","url":null,"abstract":"Abstract This article delves into the intricate relationship between the modeling parameters of an axial supersonic through-flow fan (STFF) rotor and its performance based on an active subspace method. It considers the influence of the STFF rotor key parameters on its performance. Implementing the active subspace method generates cloud maps to visualize the performance of the STFF rotor. Moreover, this study investigates the correlation between Bezier curve variables for constructing blade angles and critical performance metrics, such as the total pressure ratio and isentropic efficiency. After a 50 % chord length, the Bezier control point parameters dominate the effect on the total pressure ratio with a linear relationship. This article provides comparative flow field analyses on the blade elements with different performances under three working conditions. Under the constraint of the blade chamber turning angle, there is a linear relationship between the upper and lower limits of the isentropic efficiency distribution and total pressure ratio. This study shows that the total pressure ratio, installation angle, and maximum deflection value are positively associated. Further analysis provides an empirical formula.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48299292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Hydrogen-blended fuel is a promising resource for future generations of gas turbine engines, due to its capability of reducing carbon-based emissions. This paper presents a numerical study to assess hydrogen-enriched combustion in a laboratory-scale burner operating at a high turbulence level and under lean and stoichiometric burning conditions. Moreover, a wide range of H2 (up to 90 %) is used for enriching CH4-air combustion in combination with two different swirl levels. The results show that a high swirl intensity results in shorter flames, due to the increased turbulent intensity, which reduces the flame surface area and uniformness the reacting zone. Besides, increasing swirl intensity further increase flame temperature for a given H2-blended fuel. Overall, the results suggest that high swirl intensity in combination to lean mixtures is favorable when using H2-blended fuel with high H2 concentrations. The simulation results also demonstrate that considering radiation heat loss is influential, as it yields a reduction of the outlet temperature by not less than 100 K, bringing down NO x emissions by half.
{"title":"Numerical study of the impact of hydrogen addition, swirl intensity and equivalence ratio on methane-air combustion","authors":"M. Elbayoumi, F. Garnier, P. Seers","doi":"10.1515/tjj-2021-0048","DOIUrl":"https://doi.org/10.1515/tjj-2021-0048","url":null,"abstract":"Abstract Hydrogen-blended fuel is a promising resource for future generations of gas turbine engines, due to its capability of reducing carbon-based emissions. This paper presents a numerical study to assess hydrogen-enriched combustion in a laboratory-scale burner operating at a high turbulence level and under lean and stoichiometric burning conditions. Moreover, a wide range of H2 (up to 90 %) is used for enriching CH4-air combustion in combination with two different swirl levels. The results show that a high swirl intensity results in shorter flames, due to the increased turbulent intensity, which reduces the flame surface area and uniformness the reacting zone. Besides, increasing swirl intensity further increase flame temperature for a given H2-blended fuel. Overall, the results suggest that high swirl intensity in combination to lean mixtures is favorable when using H2-blended fuel with high H2 concentrations. The simulation results also demonstrate that considering radiation heat loss is influential, as it yields a reduction of the outlet temperature by not less than 100 K, bringing down NO x emissions by half.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42320245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The ingestion of ice crystals in aero-engine will cause engine surge, flameout, thrust loss, and even in-flight shutdown in the extreme cases, which seriously endanger the flight safety. In order to quantitatively investigate the ice crystal melting characteristic in the compressor, a method based on the compressor mean line flow was developed and validated. Results showed that the wet-bulb temperature increases as the temperature offset increases. The increase in temperature offset or decrease in particle size result in earlier or faster melting of the ice crystals in the low-pressure compressor. The rate of increase in melting ratio decreases with the increase of ice water content at the descent condition. The ambient temperature and ice crystal property are both the important factors affecting the icing risk in the compressor. Higher ambient temperature, smaller particle size or higher ice water content can increase the icing risk in the low-pressure compressor.
{"title":"Numerical investigation of ice crystal melting characteristic and icing risk in an axial compressor","authors":"W. Jia, Bowen Yang, M. Zheng, Q. Kong","doi":"10.1515/tjj-2023-0053","DOIUrl":"https://doi.org/10.1515/tjj-2023-0053","url":null,"abstract":"Abstract The ingestion of ice crystals in aero-engine will cause engine surge, flameout, thrust loss, and even in-flight shutdown in the extreme cases, which seriously endanger the flight safety. In order to quantitatively investigate the ice crystal melting characteristic in the compressor, a method based on the compressor mean line flow was developed and validated. Results showed that the wet-bulb temperature increases as the temperature offset increases. The increase in temperature offset or decrease in particle size result in earlier or faster melting of the ice crystals in the low-pressure compressor. The rate of increase in melting ratio decreases with the increase of ice water content at the descent condition. The ambient temperature and ice crystal property are both the important factors affecting the icing risk in the compressor. Higher ambient temperature, smaller particle size or higher ice water content can increase the icing risk in the low-pressure compressor.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44922074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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