Pub Date : 2023-06-01DOI: 10.36963/ijtst.2023100202
Channarong Wantha
The influences of the shape of the leading edge of the upstream plate on the transition region from steady laminar flow to unsteady flow, as well as the heat transfer from these leading edges, were numerically studied. The calculations were performed using the finite volume method in two-dimensional domains in a low Reynolds number regime with a constant incoming flow. The results show that von Kármán vortex shedding patterns start behind the rounded upstream plate at a low Reynolds number of 114. When the leading edge of the upstream plate is square, the plate experiences flow separation and the flow become unsteady at higher Reynolds numbers of around 400. The mean Nusselt number of the upstream plate increases by approximately 179% and 213% for square and rounded leading edges, respectively, for Reynolds numbers ranging from 100 to 700.
{"title":"Unsteady flow and heat transfer characteristics over the rounded and square leading-edge plate","authors":"Channarong Wantha","doi":"10.36963/ijtst.2023100202","DOIUrl":"https://doi.org/10.36963/ijtst.2023100202","url":null,"abstract":"The influences of the shape of the leading edge of the upstream plate on the transition region from steady laminar flow to unsteady flow, as well as the heat transfer from these leading edges, were numerically studied. The calculations were performed using the finite volume method in two-dimensional domains in a low Reynolds number regime with a constant incoming flow. The results show that von Kármán vortex shedding patterns start behind the rounded upstream plate at a low Reynolds number of 114. When the leading edge of the upstream plate is square, the plate experiences flow separation and the flow become unsteady at higher Reynolds numbers of around 400. The mean Nusselt number of the upstream plate increases by approximately 179% and 213% for square and rounded leading edges, respectively, for Reynolds numbers ranging from 100 to 700.","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45972590","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}
The magnetohydrodynamic (MHD) chemically reactive of Casson non-Newtonian nanofluid flow on a two-dimensional incompressible steady from stretched sheet in a porous quiescent medium with buoyancy effect is investigated numerically. Additional effects included in the originality of the model are the applied magnetic field and solar radiation effect. The Chebyshev collocation method (CCM) was used to solve the ordinary differential equations (ODEs) with MATHEMATICA 11.3 software. The present tables and graphs show the performance of fluid physical quantities, momentum flow, energy distribution, nanoparticle concentration, and velocity for various values of applicable dimensionless numbers. The numerical outcomes demonstrate the effect of different physical parameters of the fluid, and it was observed that the velocity profile increased as the thermal and mass Grashof number increased due to an increase in buoyant force caused by heat transferred from the vertical plate to the fluid but decreased as the Casson parameter increased due to a decrease in its yield stress, porosity, and magnetic parameter. Also Analyses reveal that the thermal profile reduce with an increase in variable thermal conductivity parameter. This study will be of considerable economic value to marine engineers, mechanical engineers, physicists, chemical engineers, and others since its application will help them improve their operations.
{"title":"Thermal radiation effect on Non-Newtonian Casson fluid through a porous material over a magnetic field with buoyancy","authors":"Seun Oyinkansola Mate, Adebowale Martins Obalalu, Olusegun Adebayo Ajala, Toyibat Bamidele Bakare, Amos Wale Ogunsola, Akintayo Oladimeji Akindele","doi":"10.36963/ijtst.2023100103","DOIUrl":"https://doi.org/10.36963/ijtst.2023100103","url":null,"abstract":"The magnetohydrodynamic (MHD) chemically reactive of Casson non-Newtonian nanofluid flow on a two-dimensional incompressible steady from stretched sheet in a porous quiescent medium with buoyancy effect is investigated numerically. Additional effects included in the originality of the model are the applied magnetic field and solar radiation effect. The Chebyshev collocation method (CCM) was used to solve the ordinary differential equations (ODEs) with MATHEMATICA 11.3 software. The present tables and graphs show the performance of fluid physical quantities, momentum flow, energy distribution, nanoparticle concentration, and velocity for various values of applicable dimensionless numbers. The numerical outcomes demonstrate the effect of different physical parameters of the fluid, and it was observed that the velocity profile increased as the thermal and mass Grashof number increased due to an increase in buoyant force caused by heat transferred from the vertical plate to the fluid but decreased as the Casson parameter increased due to a decrease in its yield stress, porosity, and magnetic parameter. Also Analyses reveal that the thermal profile reduce with an increase in variable thermal conductivity parameter. This study will be of considerable economic value to marine engineers, mechanical engineers, physicists, chemical engineers, and others since its application will help them improve their operations.","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69790128","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 : 2023-01-01DOI: 10.36963/ijtst.2023100201
F. Madani, B. Mahfoud, Hibet Errahmane Mahfoud
The swirling nanofluid flow driven by a revolving bottom disk of a cylindrical container under magnetic field effect and temperature gradient is examined in this study. The effects of the electrical conductivity of cylindrical walls’ on heat transfer enhancement are quantitatively investigated. The finite volume approach is used to solve the governing equations under the appropriate assumptions. This study considers four cases of combined electric conducting and insulating walls. The solid nanoparticle (copper) with volume fraction (ϕ = 0.1) is added to water. Calculations were done for fixed Reynolds number (Re=1000), Richardson number (0≤Ri ≤2), and various Hartmann numbers. The mean Nusselt number decreased as the Richardson number increased owing to stratification layers. These latter restrict heat exchanges between the cylinder’s hot and cold zones. The results show that within a particular range of Hartmann numbers, the Nusselt number increases, especially when the revolving lid is electrically conducting. The best heat transfer occurs when all of the walls are electrically conductive, which results in a 100% improvement at low Richardson values. Finally, the electrical conductivity of the revolving lid was a key factor in enhancing heat transfer.
{"title":"Influences of electrical conductivity of the cylindrical walls on heat transfer enhancement of nanofluid swirling flow","authors":"F. Madani, B. Mahfoud, Hibet Errahmane Mahfoud","doi":"10.36963/ijtst.2023100201","DOIUrl":"https://doi.org/10.36963/ijtst.2023100201","url":null,"abstract":"The swirling nanofluid flow driven by a revolving bottom disk of a cylindrical container under magnetic field effect and temperature gradient is examined in this study. The effects of the electrical conductivity of cylindrical walls’ on heat transfer enhancement are quantitatively investigated. The finite volume approach is used to solve the governing equations under the appropriate assumptions. This study considers four cases of combined electric conducting and insulating walls. The solid nanoparticle (copper) with volume fraction (ϕ = 0.1) is added to water. Calculations were done for fixed Reynolds number (Re=1000), Richardson number (0≤Ri ≤2), and various Hartmann numbers. The mean Nusselt number decreased as the Richardson number increased owing to stratification layers. These latter restrict heat exchanges between the cylinder’s hot and cold zones. The results show that within a particular range of Hartmann numbers, the Nusselt number increases, especially when the revolving lid is electrically conducting. The best heat transfer occurs when all of the walls are electrically conductive, which results in a 100% improvement at low Richardson values. Finally, the electrical conductivity of the revolving lid was a key factor in enhancing heat transfer.","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69790159","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 : 2023-01-01DOI: 10.36963/ijtst.2023100101
A. Quddus, Ajmal Shah, K. Qureshi, Ahmad Tahir, Ammar Ahmad, M. Iqbal, M. K. Ayub, Atif Mehmood
Steam-water direct contact condensation phenomenon is commonly found in many industries like chemical process industry, nuclear industry etc. In this work the injection of subcooled water into a steam filled pipe has been studied computationally. As a result of steam-water interaction within the pipe the pressure oscillates, which may cause damage to piping system or equipment. The effects of water inlet velocity, water inlet temperature, steam pressure and degree of steam superheating have been studied on the amplitude of pressure oscillations. The first and second dominant frequencies of pressure oscillations have also been obtained and studied. For most of the cases, the first dominant frequency peak was observed in the range ~ 0-1400 Hz whereas, the second dominant frequency peak was in the range ~ 2500 Hz – 3000 Hz. The first pressure peak was observed near the inlet of subcooled water such that its amplitude was increasing with increasing inlet water velocity but was nearly independent of inlet water temperature. Similarly, degree of steam superheating has no noticeable effects on pressure oscillations. It was observed that at a constant water temperature and water injecting velocity, the location of the pressure peaks was independent during the study. Further, the dominant frequency prediction map has been developed for the steam-water interaction in a pipe. The present study is assumed to be beneficial towards unfolds various important facts regarding steam-water interaction in the relevant industrial applications.
{"title":"Numerical investigation on pressure oscillations in steam condensation from injection of subcooled water","authors":"A. Quddus, Ajmal Shah, K. Qureshi, Ahmad Tahir, Ammar Ahmad, M. Iqbal, M. K. Ayub, Atif Mehmood","doi":"10.36963/ijtst.2023100101","DOIUrl":"https://doi.org/10.36963/ijtst.2023100101","url":null,"abstract":"Steam-water direct contact condensation phenomenon is commonly found in many industries like chemical process industry, nuclear industry etc. In this work the injection of subcooled water into a steam filled pipe has been studied computationally. As a result of steam-water interaction within the pipe the pressure oscillates, which may cause damage to piping system or equipment. The effects of water inlet velocity, water inlet temperature, steam pressure and degree of steam superheating have been studied on the amplitude of pressure oscillations. The first and second dominant frequencies of pressure oscillations have also been obtained and studied. For most of the cases, the first dominant frequency peak was observed in the range ~ 0-1400 Hz whereas, the second dominant frequency peak was in the range ~ 2500 Hz – 3000 Hz. The first pressure peak was observed near the inlet of subcooled water such that its amplitude was increasing with increasing inlet water velocity but was nearly independent of inlet water temperature. Similarly, degree of steam superheating has no noticeable effects on pressure oscillations. It was observed that at a constant water temperature and water injecting velocity, the location of the pressure peaks was independent during the study. Further, the dominant frequency prediction map has been developed for the steam-water interaction in a pipe. The present study is assumed to be beneficial towards unfolds various important facts regarding steam-water interaction in the relevant industrial applications.","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69790029","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 : 2023-01-01DOI: 10.36963/ijtst.2023100102
G. Y. H.
The onset of double-diffusive surface tension-driven convective motion in a fluid layer overlying a fluid-saturated anisotropic porous layer is investigated analytically in the presence of the soret effect. We considered boundaries to be insulating to temperature perturbations. The governing equation that satisfies the composite system is analyzed by the normal mode approach and solved by the regular perturbation technique for linear stability. By solving coupled equations, a mathematical expression for the critical Marangoni number is obtained. Under the effect of the anisotropy, soret parameters and the impact of various physical parameters on the start of convective motion is illustrated graphically, and the stability system is investigated.
{"title":"Onset of double diffusive surface-tension driven convection in fluid layer overlying a layer of anisotropic porous layer with soret effect","authors":"G. Y. H.","doi":"10.36963/ijtst.2023100102","DOIUrl":"https://doi.org/10.36963/ijtst.2023100102","url":null,"abstract":"The onset of double-diffusive surface tension-driven convective motion in a fluid layer overlying a fluid-saturated anisotropic porous layer is investigated analytically in the presence of the soret effect. We considered boundaries to be insulating to temperature perturbations. The governing equation that satisfies the composite system is analyzed by the normal mode approach and solved by the regular perturbation technique for linear stability. By solving coupled equations, a mathematical expression for the critical Marangoni number is obtained. Under the effect of the anisotropy, soret parameters and the impact of various physical parameters on the start of convective motion is illustrated graphically, and the stability system is investigated.","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69789864","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 : 2022-02-12DOI: 10.36963/ijtst.2022090304
V. N. Nsoga, J. Hona
In this paper, the heat transfer equation is coupled to the Navier-Stokes equations for a steady flow induced by uniform suction on two porous walls kept at different temperatures. The incompressibility of the fluid and the fact that the velocity field has two components lead to introduce the stream function in the governing equations. A similarity method is used in order to transform the resulting set of partial differential equations satisfied by the stream function and temperature into two ordinary differential equations for the same problem. The analysis is focused on the description of the behaviors of the normal and axial velocities, the streamlines, and temperature through multiple solution branches under different values of the main control parameters of the problem which are the Reynolds number, the Péclet number and the sensitivity of the thermal conductivity to the variations of temperature.
{"title":"Modeling and simulation of suction-driven flow and heat transfer with temperature-dependent thermal conductivity in a porous channel","authors":"V. N. Nsoga, J. Hona","doi":"10.36963/ijtst.2022090304","DOIUrl":"https://doi.org/10.36963/ijtst.2022090304","url":null,"abstract":"In this paper, the heat transfer equation is coupled to the Navier-Stokes equations for a steady flow induced by uniform suction on two porous walls kept at different temperatures. The incompressibility of the fluid and the fact that the velocity field has two components lead to introduce the stream function in the governing equations. A similarity method is used in order to transform the resulting set of partial differential equations satisfied by the stream function and temperature into two ordinary differential equations for the same problem. The analysis is focused on the description of the behaviors of the normal and axial velocities, the streamlines, and temperature through multiple solution branches under different values of the main control parameters of the problem which are the Reynolds number, the Péclet number and the sensitivity of the thermal conductivity to the variations of temperature.","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49458489","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 : 2022-02-12DOI: 10.36963/ijtst.2022090302
M. Abid, M. U. R. Siddiqi, A. A. Noon, M. Tahir, A. Sharif, S. Siddiqi, N. Ullah, T. Habib, M. Shayan
Tarbela Dam is one of the world largest filled dams with a capacity of 13.69 km³. It is the backbone of Pakistan, and it is used for both power generation and irrigation. Like all dam reservoirs, sedimentation decreases the life of the Tarbela dam reservoir and affects the power generating unit and tunnel equipment’s and instruments. The Finite Volume Method was used to conduct a CFD analysis to investigate different parameters that influence sedimentation. The analysis was carried out using multiphase flow (air and water) considering the summer season for maximum reservoir inflow and discharge water through spillways and tunnels. Boundary conditions were applied to a 3D geometric model that had been meshed. The spillway outlet was found to have the highest velocity. Near the spillways outlet and tunnel inlets, strong vortex motion was observed. WAPDA were suggested to redesign tunnels 3 and 4 in order to reduce sediment inflow, as well as to improve the design of the spillways.
{"title":"CFD Analysis to Predict Flow Behavior for Design and Operation of Tarbela Dam Reservoir for Different Environmental Conditions","authors":"M. Abid, M. U. R. Siddiqi, A. A. Noon, M. Tahir, A. Sharif, S. Siddiqi, N. Ullah, T. Habib, M. Shayan","doi":"10.36963/ijtst.2022090302","DOIUrl":"https://doi.org/10.36963/ijtst.2022090302","url":null,"abstract":"Tarbela Dam is one of the world largest filled dams with a capacity of 13.69 km³. It is the backbone of Pakistan, and it is used for both power generation and irrigation. Like all dam reservoirs, sedimentation decreases the life of the Tarbela dam reservoir and affects the power generating unit and tunnel equipment’s and instruments. The Finite Volume Method was used to conduct a CFD analysis to investigate different parameters that influence sedimentation. The analysis was carried out using multiphase flow (air and water) considering the summer season for maximum reservoir inflow and discharge water through spillways and tunnels. Boundary conditions were applied to a 3D geometric model that had been meshed. The spillway outlet was found to have the highest velocity. Near the spillways outlet and tunnel inlets, strong vortex motion was observed. WAPDA were suggested to redesign tunnels 3 and 4 in order to reduce sediment inflow, as well as to improve the design of the spillways.","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46913375","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 : 2022-02-12DOI: 10.36963/ijtst.2022090301
W. Riaz, A. Ahmed, K. R. Qureshi
In this paper, a critical mass flow rate (CMFR) has been obtained for three different steam generators (i.e. two marine-type and one commercial) at different inlet void fractions using the CFD method to study the sustainability of natural circulation (NC) due to depressurization in two-phase NC mode. Because of depressurization, the transients in the inlet void fraction have been considered as multiple steady-state inputs, and the range of safe operating mass flow rate has been obtained. The results show that the characteristics curves shift with inlet void fraction thus limiting the operating mass flow rate range between 0.046 kg/s to 0.050 kg/s for M_SG1 and 0.051 kg/s to 0.055 kg/s for M_SG2. The effect of pipe roughness on CMFR has also been studied. The results can be used for the optimized design of the U-tube steam generator (UTSG) that will safely perform the heat removal operation during a small break loss of coolant accident (SBLOCA).
{"title":"CFD investigation of flow reversal in inverted U-tube steam generator under two-phase natural circulation","authors":"W. Riaz, A. Ahmed, K. R. Qureshi","doi":"10.36963/ijtst.2022090301","DOIUrl":"https://doi.org/10.36963/ijtst.2022090301","url":null,"abstract":"In this paper, a critical mass flow rate (CMFR) has been obtained for three different steam generators (i.e. two marine-type and one commercial) at different inlet void fractions using the CFD method to study the sustainability of natural circulation (NC) due to depressurization in two-phase NC mode. Because of depressurization, the transients in the inlet void fraction have been considered as multiple steady-state inputs, and the range of safe operating mass flow rate has been obtained. The results show that the characteristics curves shift with inlet void fraction thus limiting the operating mass flow rate range between 0.046 kg/s to 0.050 kg/s for M_SG1 and 0.051 kg/s to 0.055 kg/s for M_SG2. The effect of pipe roughness on CMFR has also been studied. The results can be used for the optimized design of the U-tube steam generator (UTSG) that will safely perform the heat removal operation during a small break loss of coolant accident (SBLOCA).","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46848283","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 : 2022-02-12DOI: 10.36963/ijtst.2022090303
Y. Gangadharaiah, H. Nagarathnamma, S. Suma, K. Ananda
In the present article, the combined impact of vertical throughflow and temperature-reliant viscosity on the fluid-saturated anisotropic porous matrix is considered for investigation numerically by the Galerkin technique. The temperature-reliant viscosity is known to be exponential. The porous matrix is subject to continuous vertical throughflow. A parametric analysis is conducted by adjusting the following parameters: throughflow parameter, viscosity parameter, mechanical anisotropic parameter, and anisotropic thermal parameter. The findings reveal that the impacts of raising the viscosity parameter, downward throughflow parameter, and anisotropic thermal parameter delay the beginning of convection, whereas increasing mechanical anisotropic parameter and upward throughflow parameter destabilizes the porous system.
{"title":"Combined impact of variable viscosity and throughflow effects on the onset of convection in an anisotropic porous layer","authors":"Y. Gangadharaiah, H. Nagarathnamma, S. Suma, K. Ananda","doi":"10.36963/ijtst.2022090303","DOIUrl":"https://doi.org/10.36963/ijtst.2022090303","url":null,"abstract":"In the present article, the combined impact of vertical throughflow and temperature-reliant viscosity on the fluid-saturated anisotropic porous matrix is considered for investigation numerically by the Galerkin technique. The temperature-reliant viscosity is known to be exponential. The porous matrix is subject to continuous vertical throughflow. A parametric analysis is conducted by adjusting the following parameters: throughflow parameter, viscosity parameter, mechanical anisotropic parameter, and anisotropic thermal parameter. The findings reveal that the impacts of raising the viscosity parameter, downward throughflow parameter, and anisotropic thermal parameter delay the beginning of convection, whereas increasing mechanical anisotropic parameter and upward throughflow parameter destabilizes the porous system.","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46268672","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 : 2022-01-01DOI: 10.36963/ijtst.2022090203
F. Moslem, M. Masdari, K. Fedir, B. Moslem
The multi-rotors have a short working duration and produce excessive noise, which is insufficient for complicated jobs and has a negative impact on human and animal health. Nonetheless, their market is growing in popularity. As a result, low-noise products are more competitive, and aerodynamic and acoustic enhancements are essential. The goal of this research is to create a small bioinspired propeller with the same power input as a conventional propeller that achieves the same or better aerodynamic performance while reducing noise. Accordingly, an experiment looked at the effects of different operating circumstances and geometric factors on the aerodynamic and aeroacoustic performance of a small propeller with a distinctive planform shape inspired by Hemiptera. This propeller was run at eleven rotational speeds ranging from 3000 to 8000 RPM with no freestream velocity to simulate hover circumstances. When compared to the baseline propeller, the Hemiptera propeller produce greater thrust for the same power source, reduce harmonic and broadband noise, and offer a better noise level. This noise reduction might be attributed to a decrease in Hemiptera propeller force fluctuation. Furthermore, its rotational speed is lower and its figure of merit is higher than the baseline propeller at hover flying with 3N thrust. Moreover, at this force, the Hemiptera propeller shows a 2.8W power reduction and a 5 dB decrease in acoustic signature. When it comes to hover efficiency, the Hemiptera propeller outperforms the baseline propeller across the board, regardless of thrust.
{"title":"Experimental study on acoustic and aerodynamic improvement of the hemiptera-inspired propeller planform","authors":"F. Moslem, M. Masdari, K. Fedir, B. Moslem","doi":"10.36963/ijtst.2022090203","DOIUrl":"https://doi.org/10.36963/ijtst.2022090203","url":null,"abstract":"The multi-rotors have a short working duration and produce excessive noise, which is insufficient for complicated jobs and has a negative impact on human and animal health. Nonetheless, their market is growing in popularity. As a result, low-noise products are more competitive, and aerodynamic and acoustic enhancements are essential. The goal of this research is to create a small bioinspired propeller with the same power input as a conventional propeller that achieves the same or better aerodynamic performance while reducing noise. Accordingly, an experiment looked at the effects of different operating circumstances and geometric factors on the aerodynamic and aeroacoustic performance of a small propeller with a distinctive planform shape inspired by Hemiptera. This propeller was run at eleven rotational speeds ranging from 3000 to 8000 RPM with no freestream velocity to simulate hover circumstances. When compared to the baseline propeller, the Hemiptera propeller produce greater thrust for the same power source, reduce harmonic and broadband noise, and offer a better noise level. This noise reduction might be attributed to a decrease in Hemiptera propeller force fluctuation. Furthermore, its rotational speed is lower and its figure of merit is higher than the baseline propeller at hover flying with 3N thrust. Moreover, at this force, the Hemiptera propeller shows a 2.8W power reduction and a 5 dB decrease in acoustic signature. When it comes to hover efficiency, the Hemiptera propeller outperforms the baseline propeller across the board, regardless of thrust.","PeriodicalId":36637,"journal":{"name":"International Journal of Thermofluid Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42683089","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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