Pub Date : 2021-07-27DOI: 10.1109/MERCon52712.2021.9525661
Logeepan Yogaraja, Narmada Liyanagamage, K. De Silva
Estimation of energy losses in pipe flow is a prerequisite in designing pipe networks to verify the energy requirement in transferring fluid between two locations. There are two types of such energy losses namely: major losses which is caused by friction at the interface of pipe and the flow and minor losses which is caused due to local conditions such as sudden contractions, sudden expansions, and bends of the pipeline. In this paper, major and minor losses in pipe flow, calculated from empirical equations are compared with the experimental results using PVC pipes which is a popular commercial pipe category. For comparison on minor losses; Bend, Gradual contraction, Elbow bend, Gradual expansion, and 45 degrees bend which are widely used in distribution networks were used and coefficient of minor losses was used as a comparative factor. For comparison on major losses; PVC pipes with five different diameters were used and head loss vs Reynolds number variation was considered in the comparison. According to the results, the Blasius (1913) equation was found to be more accurate for actual flow, while using the Darcy-Weisbach equation found to be more predictive of the major head losses of water flow in PVC pipes.
{"title":"Comparison of Experimental Results with Empirical Relationships for Energy Losses in Pipe Flow","authors":"Logeepan Yogaraja, Narmada Liyanagamage, K. De Silva","doi":"10.1109/MERCon52712.2021.9525661","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525661","url":null,"abstract":"Estimation of energy losses in pipe flow is a prerequisite in designing pipe networks to verify the energy requirement in transferring fluid between two locations. There are two types of such energy losses namely: major losses which is caused by friction at the interface of pipe and the flow and minor losses which is caused due to local conditions such as sudden contractions, sudden expansions, and bends of the pipeline. In this paper, major and minor losses in pipe flow, calculated from empirical equations are compared with the experimental results using PVC pipes which is a popular commercial pipe category. For comparison on minor losses; Bend, Gradual contraction, Elbow bend, Gradual expansion, and 45 degrees bend which are widely used in distribution networks were used and coefficient of minor losses was used as a comparative factor. For comparison on major losses; PVC pipes with five different diameters were used and head loss vs Reynolds number variation was considered in the comparison. According to the results, the Blasius (1913) equation was found to be more accurate for actual flow, while using the Darcy-Weisbach equation found to be more predictive of the major head losses of water flow in PVC pipes.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"13 1","pages":"522-527"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87815510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1109/MERCon52712.2021.9525737
A. Dassanayake, Y. Fujii, A. Thirukumaran
Fluid in porous rocks affect the performance of rock structures and thus it is important to determine the effective stress in wide range of rock engineering applications. In this study, Bibai Sandstone, a hard-clastic rock, was subjected to multistage and single stage triaxial tests to determine the coefficients of effective stress corresponding to peak and residual strength states ($alpha_{-text{Peak}}$ and $alpha_{-text{Residual}}$) through, Modified Failure Envelope Method (MFEM). The coefficients of effective stress of intact and fractured Bibai Sandstone specimens ($alpha_{-text{Biot}^{prime}mathrm{s}}$ and $alpha_{-text{Fractured}}$) were determined using hydrostatic compression test and compared with the values obtained for $alpha_{-text{Peak}}$ and $alpha_{-text{Residual}}$ by MFEM. Microstructure analysis was carried out on the images of blue resin impregnated thin sections using Imagej software and a post-compression macrostructure analysis was performed using micro-focus xray computed tomography (CT). $alpha_{-text{Biot}^{prime}mathrm{s}}$ and $alpha_{-text{Peak}}$ decreased with increasing confining pressure which was related to the microstructure of the rocks. Further, the applicability of MFEM were discussed.
{"title":"Effective Stress Coefficient through MFEM and Confining Pressure Dependency of Bibai Sandstone","authors":"A. Dassanayake, Y. Fujii, A. Thirukumaran","doi":"10.1109/MERCon52712.2021.9525737","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525737","url":null,"abstract":"Fluid in porous rocks affect the performance of rock structures and thus it is important to determine the effective stress in wide range of rock engineering applications. In this study, Bibai Sandstone, a hard-clastic rock, was subjected to multistage and single stage triaxial tests to determine the coefficients of effective stress corresponding to peak and residual strength states ($alpha_{-text{Peak}}$ and $alpha_{-text{Residual}}$) through, Modified Failure Envelope Method (MFEM). The coefficients of effective stress of intact and fractured Bibai Sandstone specimens ($alpha_{-text{Biot}^{prime}mathrm{s}}$ and $alpha_{-text{Fractured}}$) were determined using hydrostatic compression test and compared with the values obtained for $alpha_{-text{Peak}}$ and $alpha_{-text{Residual}}$ by MFEM. Microstructure analysis was carried out on the images of blue resin impregnated thin sections using Imagej software and a post-compression macrostructure analysis was performed using micro-focus xray computed tomography (CT). $alpha_{-text{Biot}^{prime}mathrm{s}}$ and $alpha_{-text{Peak}}$ decreased with increasing confining pressure which was related to the microstructure of the rocks. Further, the applicability of MFEM were discussed.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"143 1","pages":"409-414"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86581195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1109/MERCon52712.2021.9525791
M. Hettiarachchi
Currently adopted assessment practices in the subject module; Design of Steel Structures at the Department of Civil Engineering at the University of Moratuwa, Sri Lanka are discussed in the context of recent pedagogical practice. A self-appraisal is done to ascertain whether learning outcomes of the subject module are appropriately and adequately assessed. It was seen that little attempt had been made in the past to explicitly link assessments with the outcomes at the time of assessment. The self-appraisal identified the inadequacies which has since been addressed.
{"title":"A Reflection on Assessing Learning Outcomes","authors":"M. Hettiarachchi","doi":"10.1109/MERCon52712.2021.9525791","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525791","url":null,"abstract":"Currently adopted assessment practices in the subject module; Design of Steel Structures at the Department of Civil Engineering at the University of Moratuwa, Sri Lanka are discussed in the context of recent pedagogical practice. A self-appraisal is done to ascertain whether learning outcomes of the subject module are appropriately and adequately assessed. It was seen that little attempt had been made in the past to explicitly link assessments with the outcomes at the time of assessment. The self-appraisal identified the inadequacies which has since been addressed.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"12 1","pages":"734-740"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90385018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1109/MERCon52712.2021.9525668
Hiroshaan Vadivel, K. S. Priyanayana, A. Jayasekara
Wheelchairs are the evaded partner in the lives of many differently-abled people to support their day-to-day activities. Manual and powered wheelchairs fail to meet the docking behavior for a specific task on the table. As the main aim of this research, a human study was performed to identify the docking behavior of a wheelchair to the table or desk in four different scenarios such as writing, reading, eating, and using a Laptop. With 3D point cloud data, this paper introduces an algorithm for automatically detecting secure docking locations at rectangular docking structures (tables, desks) with proper alignment knowledge. Within the sense of delivering advanced driving assistance for powered wheelchair users, the secure docking areas will then be given as priorities to an autonomous route designer. The experimental findings show that the proposed wheelchair docking system is capable of maintaining user comfort during approaches.
{"title":"Enhancing the Capabilities of Approaching to Service Scenarios and Settling for Intelligent Wheelchair Robots","authors":"Hiroshaan Vadivel, K. S. Priyanayana, A. Jayasekara","doi":"10.1109/MERCon52712.2021.9525668","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525668","url":null,"abstract":"Wheelchairs are the evaded partner in the lives of many differently-abled people to support their day-to-day activities. Manual and powered wheelchairs fail to meet the docking behavior for a specific task on the table. As the main aim of this research, a human study was performed to identify the docking behavior of a wheelchair to the table or desk in four different scenarios such as writing, reading, eating, and using a Laptop. With 3D point cloud data, this paper introduces an algorithm for automatically detecting secure docking locations at rectangular docking structures (tables, desks) with proper alignment knowledge. Within the sense of delivering advanced driving assistance for powered wheelchair users, the secure docking areas will then be given as priorities to an autonomous route designer. The experimental findings show that the proposed wheelchair docking system is capable of maintaining user comfort during approaches.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"37 1","pages":"711-716"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77517085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1109/MERCon52712.2021.9525709
Sudeepa Nadeeshan, A. Perera
Accurate Bus Arrival Time (BAT) prediction is a measure of the quality of the public transport system. Intercity buses usually run for longer distances (e.g. 100 km+), and their frequency is lower compared to short-distance buses. It is essential to predict BAT accurately in order to improve the customer satisfaction of the passengers in the intermediate stops when the static schedules highly deviate from the displayed ones. We are introducing unidirectional and bidirectional multi-step LSTM Networks for link-based travel time prediction. We have derived two feature sets from the GPS data, weather data, and other augmented data considering the low frequency of the buses to test the models. To the best of our knowledge, this is the first work done to solve the BAT problem in Sri Lankan traffic conditions.
{"title":"Multi-Step Bidirectional LSTM for Low Frequent Bus Travel Time Prediction","authors":"Sudeepa Nadeeshan, A. Perera","doi":"10.1109/MERCon52712.2021.9525709","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525709","url":null,"abstract":"Accurate Bus Arrival Time (BAT) prediction is a measure of the quality of the public transport system. Intercity buses usually run for longer distances (e.g. 100 km+), and their frequency is lower compared to short-distance buses. It is essential to predict BAT accurately in order to improve the customer satisfaction of the passengers in the intermediate stops when the static schedules highly deviate from the displayed ones. We are introducing unidirectional and bidirectional multi-step LSTM Networks for link-based travel time prediction. We have derived two feature sets from the GPS data, weather data, and other augmented data considering the low frequency of the buses to test the models. To the best of our knowledge, this is the first work done to solve the BAT problem in Sri Lankan traffic conditions.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"93 2-3 1","pages":"462-467"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78135025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1109/MERCon52712.2021.9525765
Branavan Arulmoly, Chaminda Konthesingha, A. Nanayakkara
This study investigates the performance evaluation of lime-cement mortar comprised of manufactured sand and offshore sand as the river sand alternatives. The most common mortars suggested by the standards such as S and N types were selected and five mixes were prepared for each type. Different sand compositions such as river sand, manufactured sand, and blended sand with manufactured sand and offshore sand were used in the mixes. The performance of mortars with sand replacements was investigated based on the fresh and hardened properties. The experimental results were undergone for a one-way analysis of variance (ANOVA) test to check whether the selected sand types and replacements statistically and significantly impacted the properties of mortar. Results revealed that the selected replacements statistically and significantly influenced the workability, compressive strength, and flexural strength while no significant improvements were noticed with the workable life of mortars. Mortars with blended sand considerably improved the performance against capillary water absorption than a mortar with river sand.
{"title":"Influence of Blended Fine Aggregates on the Performance of Lime - Cement Mortar — A Statistical Approach","authors":"Branavan Arulmoly, Chaminda Konthesingha, A. Nanayakkara","doi":"10.1109/MERCon52712.2021.9525765","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525765","url":null,"abstract":"This study investigates the performance evaluation of lime-cement mortar comprised of manufactured sand and offshore sand as the river sand alternatives. The most common mortars suggested by the standards such as S and N types were selected and five mixes were prepared for each type. Different sand compositions such as river sand, manufactured sand, and blended sand with manufactured sand and offshore sand were used in the mixes. The performance of mortars with sand replacements was investigated based on the fresh and hardened properties. The experimental results were undergone for a one-way analysis of variance (ANOVA) test to check whether the selected sand types and replacements statistically and significantly impacted the properties of mortar. Results revealed that the selected replacements statistically and significantly influenced the workability, compressive strength, and flexural strength while no significant improvements were noticed with the workable life of mortars. Mortars with blended sand considerably improved the performance against capillary water absorption than a mortar with river sand.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"3 1","pages":"275-280"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91261125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1109/MERCon52712.2021.9525664
A. Ratnakumar, A. Samarasekara, D. Amarasinghe, L. Karunanayake
Rice straw is the agricultural production residue which is considered as an agricultural waste. Though it is utilized in various ways, there is a greater possibility for value addition by disintegrating nanofibrillated cellulose from this commercially underutilized waste material. In this study, nanofibrillated cellulose (NFC) was individualized from locally available rice straw variety Murunkan via chemo-mechanical treatments. Firstly, cellulose fibers were extracted from rice straw via a set of chemical processes. Then using high intensity ultrasonication (HIUS) treatment acquired cellulose fibers were individualized into nanofibrillated cellulose. Structural, morphological and thermal behavior of NFC throughout the chemo-mechanical processes were studied. FTIR analysis confirmed that the chemical composition of nanofibrillated cellulose was mainly cellulose where amorphous natured hemicellulose and lignin were effectively removed during chemical processes. From the set of chemical processes, Murunkan variety yielded around 34 per cent cellulose fibers. Out of these cellulose fibers around 17 per cent NFC was individualized via the HIUS treatment. Microscopy study showed that the diameters of the extracted NFC ranged between 100 to 200 nm. Findings of this study will not only add value to the rice straw but also embrace sustainable transition to a bioeconomy in the country.
{"title":"Individualization of Nanofibrillated Cellulose from Sri Lankan Rice Straw: Structural Characteristics and Thermal Properties","authors":"A. Ratnakumar, A. Samarasekara, D. Amarasinghe, L. Karunanayake","doi":"10.1109/MERCon52712.2021.9525664","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525664","url":null,"abstract":"Rice straw is the agricultural production residue which is considered as an agricultural waste. Though it is utilized in various ways, there is a greater possibility for value addition by disintegrating nanofibrillated cellulose from this commercially underutilized waste material. In this study, nanofibrillated cellulose (NFC) was individualized from locally available rice straw variety Murunkan via chemo-mechanical treatments. Firstly, cellulose fibers were extracted from rice straw via a set of chemical processes. Then using high intensity ultrasonication (HIUS) treatment acquired cellulose fibers were individualized into nanofibrillated cellulose. Structural, morphological and thermal behavior of NFC throughout the chemo-mechanical processes were studied. FTIR analysis confirmed that the chemical composition of nanofibrillated cellulose was mainly cellulose where amorphous natured hemicellulose and lignin were effectively removed during chemical processes. From the set of chemical processes, Murunkan variety yielded around 34 per cent cellulose fibers. Out of these cellulose fibers around 17 per cent NFC was individualized via the HIUS treatment. Microscopy study showed that the diameters of the extracted NFC ranged between 100 to 200 nm. Findings of this study will not only add value to the rice straw but also embrace sustainable transition to a bioeconomy in the country.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"151 1","pages":"37-42"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85615130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1109/MERCon52712.2021.9525763
C. Subramaniyam, Lalith Rajapakse
Groundwater depletion during the low rainfall period and flash floods during the monsoonal period are the predominant issues identified in the Jaffna Peninsula, the Northern part of Sri Lanka. The managed artificial recharge of groundwater aquifers using excess runoff is considered a feasible solution. Analytical Hierarchy Process (AHP) analysis was initially performed to develop an Artificial Groundwater Recharging Potential Zone Mapping (GWPZM) based on seven different groundwater behavioural influencing factors. A water resource action plan was developed to propose suitable stormwater quality and quantity controlling structures according to the unique hydrogeological behaviour of the Jaffna Peninsula. The proposed major artificial recharging units were introduced in the areas with adequate groundwater infiltration potential sites. Recharging reservoirs were assigned for the lagoon region with silt sedimentation. Dry wells were proposed for the region adjacent to the floodplain along with stormwater quality control structures. Paleochannel footprints were not found in the preliminary studies. Flood analysis using Rainfall-Runoff-Inundation (RRI) Model indicated that the simulated inundation area of the 2017 flood event is reduced by 41.47% after the establishment of artificial recharging techniques. A fundamental idea of Web GIS was suggested for real-time monitoring purposes.
{"title":"A Study on Surface Water - Groundwater Interaction in the Jaffna Peninsula, Sri Lanka","authors":"C. Subramaniyam, Lalith Rajapakse","doi":"10.1109/MERCon52712.2021.9525763","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525763","url":null,"abstract":"Groundwater depletion during the low rainfall period and flash floods during the monsoonal period are the predominant issues identified in the Jaffna Peninsula, the Northern part of Sri Lanka. The managed artificial recharge of groundwater aquifers using excess runoff is considered a feasible solution. Analytical Hierarchy Process (AHP) analysis was initially performed to develop an Artificial Groundwater Recharging Potential Zone Mapping (GWPZM) based on seven different groundwater behavioural influencing factors. A water resource action plan was developed to propose suitable stormwater quality and quantity controlling structures according to the unique hydrogeological behaviour of the Jaffna Peninsula. The proposed major artificial recharging units were introduced in the areas with adequate groundwater infiltration potential sites. Recharging reservoirs were assigned for the lagoon region with silt sedimentation. Dry wells were proposed for the region adjacent to the floodplain along with stormwater quality control structures. Paleochannel footprints were not found in the preliminary studies. Flood analysis using Rainfall-Runoff-Inundation (RRI) Model indicated that the simulated inundation area of the 2017 flood event is reduced by 41.47% after the establishment of artificial recharging techniques. A fundamental idea of Web GIS was suggested for real-time monitoring purposes.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"18 1","pages":"510-515"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83992539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1109/MERCon52712.2021.9525728
S. Saparamadu, S. Bandara
Air passengers encounter many difficulties at different mandatory service centers at the airport. To enhance the functionality of the service centers available literature highlights several simulation and analytical models to minimize the delays and queues at mandatory service centers. A different mechanism of placing frictions between the mandatory service centers to optimize the passenger delays is used in this research. It helps when the departure rate of the first service center is greater than the service rate of the second service center. This research can be used to find expected delays at service centers. Furthermore, this can be utilized to decide on the placement of suitable frictions before mandatory service centers in a proper manner to suit the arrival and departure procedures to minimize overall passenger delays.
{"title":"Estimating Passenger Delays at Airport Terminal Service Centers","authors":"S. Saparamadu, S. Bandara","doi":"10.1109/MERCon52712.2021.9525728","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525728","url":null,"abstract":"Air passengers encounter many difficulties at different mandatory service centers at the airport. To enhance the functionality of the service centers available literature highlights several simulation and analytical models to minimize the delays and queues at mandatory service centers. A different mechanism of placing frictions between the mandatory service centers to optimize the passenger delays is used in this research. It helps when the departure rate of the first service center is greater than the service rate of the second service center. This research can be used to find expected delays at service centers. Furthermore, this can be utilized to decide on the placement of suitable frictions before mandatory service centers in a proper manner to suit the arrival and departure procedures to minimize overall passenger delays.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"1 1","pages":"493-497"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82388151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Accuracy of numerical predictions of film cooling performance is vital to investigate for designing and analyzing film cooling technology. Three RANS turbulence models of Standard k-$varepsilon$ (SKE), Standard k-$omega$ (SKW) and Shear Stress Transport methods (SST k-$omega$) were selected and used to simulate low blowing ratio cases ($mathrm{M} < 1$). The three blowing ratio of 0.2, 0.5 and 0.7 were produced using an inclined cylindrical hole of 30 degree made on a flat plate. ANSYS CFX solver was used to simulate the selected experimental cases with density ratio (DR) of 1.8. The numerical results of the three turbulence models under the blowing rate of 0.2 have not captured the lateral distribution of coolant correctly. SKW under the blowing rate of 0.5 have accurately predicted the effectiveness in mixing region. Centerline adiabatic effectiveness generated by SKW model was in a good agreement with experimental results for the blowing rate of 0.5. For the blowing rate of 0.2, the centerline effectiveness were best predicted by the SST model while SKW and SKE models can be used to predict the adiabatic effectiveness with considerable accuracy in lateral direction in the region of $mathrm{X}/mathrm{D} < 10$.
{"title":"Evaluation of RANS Turbulence Models for Prediction of Lateral Film Cooling Effectiveness at Low Blowing Ratios","authors":"Pasan Sanjeeva, E.G.D.R. Thilakarathna, Chanaka Mallikarachchi, Chathura Ranasinghe","doi":"10.1109/MERCon52712.2021.9525723","DOIUrl":"https://doi.org/10.1109/MERCon52712.2021.9525723","url":null,"abstract":"Accuracy of numerical predictions of film cooling performance is vital to investigate for designing and analyzing film cooling technology. Three RANS turbulence models of Standard k-$varepsilon$ (SKE), Standard k-$omega$ (SKW) and Shear Stress Transport methods (SST k-$omega$) were selected and used to simulate low blowing ratio cases ($mathrm{M} < 1$). The three blowing ratio of 0.2, 0.5 and 0.7 were produced using an inclined cylindrical hole of 30 degree made on a flat plate. ANSYS CFX solver was used to simulate the selected experimental cases with density ratio (DR) of 1.8. The numerical results of the three turbulence models under the blowing rate of 0.2 have not captured the lateral distribution of coolant correctly. SKW under the blowing rate of 0.5 have accurately predicted the effectiveness in mixing region. Centerline adiabatic effectiveness generated by SKW model was in a good agreement with experimental results for the blowing rate of 0.5. For the blowing rate of 0.2, the centerline effectiveness were best predicted by the SST model while SKW and SKE models can be used to predict the adiabatic effectiveness with considerable accuracy in lateral direction in the region of $mathrm{X}/mathrm{D} < 10$.","PeriodicalId":6855,"journal":{"name":"2021 Moratuwa Engineering Research Conference (MERCon)","volume":"68 1","pages":"339-344"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76528097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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