Silica particles were used as a filler to produce silica-epoxy composite. Silica particles with two mean diameters of 1 μm and 37 μm and filler content of 20, 30, 40, and 60 wt. % were used to investigate the effect of particle size and filler content on the fracture behavior of epoxy resin composite, respectively. The fractural behavior of composites was characterized by linear elastic fracture mechanics according to standard of ASTM-D5045 in which three-point bending test procedure was used to investigate plane-strain fracture toughness (Kıc) and strain energy release rate (Gıc) of the composite specimens. Glass transient temperatures of the samples were evaluated by using differential scanning calorimetry (DSC). Fracture surfaces of the produced specimens were examined by SEM. The highest Young’s modulus value was 10.48 GPa for the sample produced with 37 μm particle size and 60 wt. % filler content and it was found that a considerable increase was obtained according to the 3.05 MPa values of the unfilled epoxy. Experimental results show that fracture toughness value of the silica filled epoxy composite was improved by 98% compared to unfilled epoxy.
{"title":"Effect of silica particle size and filler content on the fracture properties of epoxy resin composite","authors":"Zafer Azem, U. Malayoğlu, B. Uyulgan","doi":"10.32908/hthp.v50.999","DOIUrl":"https://doi.org/10.32908/hthp.v50.999","url":null,"abstract":"Silica particles were used as a filler to produce silica-epoxy composite. Silica particles with two mean diameters of 1 μm and 37 μm and filler content of 20, 30, 40, and 60 wt. % were used to investigate the effect of particle size and filler content on the fracture behavior of epoxy resin composite, respectively. The fractural behavior of composites was characterized by linear elastic fracture mechanics according to standard of ASTM-D5045 in which three-point bending test procedure was used to investigate plane-strain fracture toughness (Kıc) and strain energy release rate (Gıc) of the composite specimens. Glass transient temperatures of the samples were evaluated by using differential scanning calorimetry (DSC). Fracture surfaces of the produced specimens were examined by SEM. The highest Young’s modulus value was 10.48 GPa for the sample produced with 37 μm particle size and 60 wt. % filler content and it was found that a considerable increase was obtained according to the 3.05 MPa values of the unfilled epoxy. Experimental results show that fracture toughness value of the silica filled epoxy composite was improved by 98% compared to unfilled epoxy.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442781","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}
B. Hay, N. Milošević, J. Hameury, N. Stepanić, G. Failleau, Y. Garcia, A. Koenen, J. Filtz
An inter-laboratory comparison has been organized between LNE and Institute VINČA, respectively French National Metrology Institute and Serbian Designated Institute for thermal properties metrology, on thermal conductivity measurements by the guarded hot plate method. The main objective was to validate the measurement capabilities of VINČA in terms of thermal conductivity in the temperature range from 10 °C to 50 °C by using the facility improved in the frame of the European project Eura-Thermal. The measurements were carried out on expanded polystyrene boards using guarded hot plate apparatuses (two-specimen GHP apparatuses) in accordance with the international standard ISO 8302. The measurement programme was defined taking into account the major characteristics of the guarded hot plate apparatuses used, such as specimen dimensions and temperature and thermal conductivity ranges. Specimens were machined by LNE from a same batch for both participants. Prior to the measurements, the homogeneity of the set of specimens, as well as the influence of a variation of density of the expanded polystyrene on the thermal conductivity measurements were studied by VINČA.
{"title":"Inter-laboratory comparison on thermal conductivity measurements by the guarded hot plate method between LNE and Institute VINČA","authors":"B. Hay, N. Milošević, J. Hameury, N. Stepanić, G. Failleau, Y. Garcia, A. Koenen, J. Filtz","doi":"10.32908/hthp.v50.1001","DOIUrl":"https://doi.org/10.32908/hthp.v50.1001","url":null,"abstract":"An inter-laboratory comparison has been organized between LNE and Institute VINČA, respectively French National Metrology Institute and Serbian Designated Institute for thermal properties metrology, on thermal conductivity measurements by the guarded hot plate method. The main objective was to validate the measurement capabilities of VINČA in terms of thermal conductivity in the temperature range from 10 °C to 50 °C by using the facility improved in the frame of the European project Eura-Thermal. The measurements were carried out on expanded polystyrene boards using guarded hot plate apparatuses (two-specimen GHP apparatuses) in accordance with the international standard ISO 8302. The measurement programme was defined taking into account the major characteristics of the guarded hot plate apparatuses used, such as specimen dimensions and temperature and thermal conductivity ranges. Specimens were machined by LNE from a same batch for both participants. Prior to the measurements, the homogeneity of the set of specimens, as well as the influence of a variation of density of the expanded polystyrene on the thermal conductivity measurements were studied by VINČA.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442397","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}
Jieren Luo, Qiuhui Yan, Zhao-zan Feng, M. Zhang, Yaxin Yang
Supercritical water gasification (SCWG) is a promising technology for clean and efficient utilization of carbonaceous organic materials at high temperature and pressure. Coal/biomass co-gasification in supercritical water (SCW) is a better choice for both coal and biomass to offset their disadvantages. Therefore, based on the experimental results of coal/carboxymethylcellulose (CMC, as a model compound of biomass) co-gasification in SCW by continuous flow thermal-catalytic reaction system at a reactor wall temperature of 650 �C, pressure of 25 MPa, a residence time 30 s and 0.1 wt% NaOH additive, the effects of heat transfer efficiency, heat supply methods, and CMC fraction on exergy and energy efficiency of reactor (the core device in reaction system) were investigated. The results show that energy and exergy efficiencies are in excess of 69% and 43%, respectively. The priority order of heat supply for the reactor is as follow: lower temperature heat source > higher temperature heat source > direct electricity heat supply method. The heat transfer efficiency has great influence on the energy and exergy efficiencies in terms of thermophysics. The higher CMC fraction is helpful to improve exergy efficiency.
{"title":"Exergy and energy analysis on coal/biomass co-gasification in supercritical water","authors":"Jieren Luo, Qiuhui Yan, Zhao-zan Feng, M. Zhang, Yaxin Yang","doi":"10.32908/hthp.v50.927","DOIUrl":"https://doi.org/10.32908/hthp.v50.927","url":null,"abstract":"Supercritical water gasification (SCWG) is a promising technology for clean and efficient utilization of carbonaceous organic materials at high temperature and pressure. Coal/biomass co-gasification in supercritical water (SCW) is a better choice for both coal and biomass to offset their disadvantages. Therefore, based on the experimental results of coal/carboxymethylcellulose (CMC, as a model compound of biomass) co-gasification in SCW by continuous flow thermal-catalytic reaction system at a reactor wall temperature of 650 �C, pressure of 25 MPa, a residence time 30 s and 0.1 wt% NaOH additive, the effects of heat transfer efficiency, heat supply methods, and CMC fraction on exergy and energy efficiency of reactor (the core device in reaction system) were investigated. The results show that energy and exergy efficiencies are in excess of 69% and 43%, respectively. The priority order of heat supply for the reactor is as follow: lower temperature heat source > higher temperature heat source > direct electricity heat supply method. The heat transfer efficiency has great influence on the energy and exergy efficiencies in terms of thermophysics. The higher CMC fraction is helpful to improve exergy efficiency.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442539","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}
Jinjuan Sun, Shaobo Chen, K. Yao, Ying Chen, X. Yao
In present paper, we perform first principles based on density functional theory to investigate the effect of high pressure on phononic, electronic, elastic and thermodynamic properties of ScSi. It is found that phonon dispersion curve of ScSi has no virtual frequency within a given pressure range from 0 GPa to 35 GPa, indicating that the material is thermodynamically stable. When a given pressure is larger than 40 GPa, ScSi is thermodynamically instable and will occurs phase transition. Band structure and density of states confirm that ScSi is metallic. The elastic constant Cij increases with increasing pressure, and meets the Born�s criterion, which shows that ScSi possesses mechanical stability. Meanwhile, the ductility and toughness of material increase with increasing pressure, which is very conducive to industrial applications. In addition, Debye temperature and sound velocity increase linearly with pressures, indicating that appropriate pressure can improve elasticity, hardness, melting point and specific heat.
{"title":"Phononic, electronic, elastic and thermodynamic properties of ScSi under high pressure via first principles calculations","authors":"Jinjuan Sun, Shaobo Chen, K. Yao, Ying Chen, X. Yao","doi":"10.32908/hthp.v50.939","DOIUrl":"https://doi.org/10.32908/hthp.v50.939","url":null,"abstract":"In present paper, we perform first principles based on density functional theory to investigate the effect of high pressure on phononic, electronic, elastic and thermodynamic properties of ScSi. It is found that phonon dispersion curve of ScSi has no virtual frequency within a given pressure range from 0 GPa to 35 GPa, indicating that the material is thermodynamically stable. When a given pressure is larger than 40 GPa, ScSi is thermodynamically instable and will occurs phase transition. Band structure and density of states confirm that ScSi is metallic. The elastic constant Cij increases with increasing pressure, and meets the Born�s criterion, which shows that ScSi possesses mechanical stability. Meanwhile, the ductility and toughness of material increase with increasing pressure, which is very conducive to industrial applications. In addition, Debye temperature and sound velocity increase linearly with pressures, indicating that appropriate pressure can improve elasticity, hardness, melting point and specific heat.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442610","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}
{"title":"Obituary: Academician Vladimir E. Fortov (1946–2020)","authors":" ","doi":"10.32908/hthp.v50.1171","DOIUrl":"https://doi.org/10.32908/hthp.v50.1171","url":null,"abstract":"","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442831","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}
D. Giuranno, S. Amore, R. Novakovic, Corrado Tomasi, E. Ricci
Conventional high-chromium ferritic / martensitic steels, such as T91 and AISI 316 L as well as the new oxide dispersed strengthened (ODS) steels, i.e. Fe-Cr (ferritic or martensitic) with a fine Y2O3 dispersion, are promising candidates as structural materials for applications in aggressive environments. In order to improve the efficiency and lifetime of structural materials for liquid metal fast reactor (LMFR), where liquid lead (Pb) is used as coolant, the investigations are currently focused on the interfacial phenomena occurring at the liquid Pb/steel interfaces. The better understanding of the interfacial phenomena is the key issue for the selection of structural materials meeting the requirements of the demanding application. In the present work, a fundamental study on the wetting characteristics and the interfacial phenomena of liquid Pb in contact with T91, AISI 316L, ODS- 12Cr and ODS-14Cr steels over the temperature range 550�820�C and under different oxygen containing atmospheres is reported.
{"title":"Wetting property of liquid Pb on different steel candidates as structural materials for the Generation IV nuclear reactors","authors":"D. Giuranno, S. Amore, R. Novakovic, Corrado Tomasi, E. Ricci","doi":"10.32908/hthp.v50.871","DOIUrl":"https://doi.org/10.32908/hthp.v50.871","url":null,"abstract":"Conventional high-chromium ferritic / martensitic steels, such as T91 and AISI 316 L as well as the new oxide dispersed strengthened (ODS) steels, i.e. Fe-Cr (ferritic or martensitic) with a fine Y2O3 dispersion, are promising candidates as structural materials for applications in aggressive environments. In order to improve the efficiency and lifetime of structural materials for liquid metal fast reactor (LMFR), where liquid lead (Pb) is used as coolant, the investigations are currently focused on the interfacial phenomena occurring at the liquid Pb/steel interfaces. The better understanding of the interfacial phenomena is the key issue for the selection of structural materials meeting the requirements of the demanding application. In the present work, a fundamental study on the wetting characteristics and the interfacial phenomena of liquid Pb in contact with T91, AISI 316L, ODS- 12Cr and ODS-14Cr steels over the temperature range 550�820�C and under different oxygen containing atmospheres is reported.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442958","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}
The thermodynamic properties of grossular garnet (Ca3Al2Si3O12) were determined as a function of pressure and temperature in this study. With a numerical iterative procedure, the unit-cell volume, adiabatic bulk modulus, thermal expansion, heat capacity, and Gr�neisen parameters of grossular up to 25 GPa, 2000 K were extracted from experimental elastic wave velocities at high temperature and high pressure conditions. The calculated unit-cell volume and adiabatic bulk modulus agree well with the previous studies. The results imply that our calculated thermal expansion, heat capacity, and Gr�neisen parameters of grossular are all decrease with elevated pressure, and both thermal expansion and heat capacity show nonlinear pressure dependences. On the other hand, the Gr�neisen parameter shows a linear pressure dependence. The pressure derivative of thermal expansion display a regularity increase with temperature, while the pressure derivatives of heat capacity and Gr�neisen parameters display a rapid decrease at low temperature and a slow growth above ~1000 K.
{"title":"Thermal expansion, heat capacity and Gr�neisen parameter of grossular at high temperature and high pressure","authors":"Chang Su, Yonggang Liu","doi":"10.32908/hthp.v50.957","DOIUrl":"https://doi.org/10.32908/hthp.v50.957","url":null,"abstract":"The thermodynamic properties of grossular garnet (Ca3Al2Si3O12) were determined as a function of pressure and temperature in this study. With a numerical iterative procedure, the unit-cell volume, adiabatic bulk modulus, thermal expansion, heat capacity, and Gr�neisen parameters of grossular up to 25 GPa, 2000 K were extracted from experimental elastic wave velocities at high temperature and high pressure conditions. The calculated unit-cell volume and adiabatic bulk modulus agree well with the previous studies. The results imply that our calculated thermal expansion, heat capacity, and Gr�neisen parameters of grossular are all decrease with elevated pressure, and both thermal expansion and heat capacity show nonlinear pressure dependences. On the other hand, the Gr�neisen parameter shows a linear pressure dependence. The pressure derivative of thermal expansion display a regularity increase with temperature, while the pressure derivatives of heat capacity and Gr�neisen parameters display a rapid decrease at low temperature and a slow growth above ~1000 K.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442670","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}
R. M. Cotta, P. C. Pontes, Adam H. R. Sousa, C. Naveira-Cotta, K. Lisboa
Heat and mass transfer enhancement techniques, either passive or active, have an important role in the more general goal of process intensification in modern engineering developments. In this context, the study of transport phenomena at the nano- and micro-scales aims far beyond the plain miniaturization of devices, being mainly directed towards process efficiency improvement and lower energy and raw materials consumption. The analysis of heat and mass transfer at such scales has required the development or extension of both theoretical and experimental methodologies. In light of the inherent multiscale nature of microfluidic devices, classical fully numerical methodologies often require large refined meshes with associated costly computations. A hybrid numerical-analytical approach for the analysis of microfluidic and thermal micro-systems is here reviewed, which includes a computational-analytical integral transform method for partial differential direct problems, that, together with mixed symbolic-numerical computations, lead to robust cost-effective algorithms for micro-scale transport phenomena analysis. Examples of this hybrid approach in selected applications are then examined more closely, including micro-reactors for continuous biodiesel synthesis with multiple reactive interfaces and three-dimensional thermal micro-devices with solid-fluid thermal conjugation.
{"title":"Computational-analytical simulation of microsystems in process intensification","authors":"R. M. Cotta, P. C. Pontes, Adam H. R. Sousa, C. Naveira-Cotta, K. Lisboa","doi":"10.32908/hthp.v50.1189","DOIUrl":"https://doi.org/10.32908/hthp.v50.1189","url":null,"abstract":"Heat and mass transfer enhancement techniques, either passive or active, have an important role in the more general goal of process intensification in modern engineering developments. In this context, the study of transport phenomena at the nano- and micro-scales aims far beyond the plain miniaturization of devices, being mainly directed towards process efficiency improvement and lower energy and raw materials consumption. The analysis of heat and mass transfer at such scales has required the development or extension of both theoretical and experimental methodologies. In light of the inherent multiscale nature of microfluidic devices, classical fully numerical methodologies often require large refined meshes with associated costly computations. A hybrid numerical-analytical approach for the analysis of microfluidic and thermal micro-systems is here reviewed, which includes a computational-analytical integral transform method for partial differential direct problems, that, together with mixed symbolic-numerical computations, lead to robust cost-effective algorithms for micro-scale transport phenomena analysis. Examples of this hybrid approach in selected applications are then examined more closely, including micro-reactors for continuous biodiesel synthesis with multiple reactive interfaces and three-dimensional thermal micro-devices with solid-fluid thermal conjugation.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442850","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}
In the present work, we have used phenomological models for analyzing the impact of shape and size on energy band gap in semiconducting nanomaterial compounds. The models used presently are Qi model, Bond energy model and Guisbiers model. The extension of melting temperature expression for nanomaterials of the models considered is done and shape and size dependent expression of energy band gap is obtained. In this paper, we have taken group III-V semiconductor compound nanomaterials i.e., AlN, GaN, InN, GaAs and InAs. It is clear from the results obtained that decrease in the size of the semiconductor compound nanomaterials led to band gap expansion and this increase is significant for particle size below 5 nm. Comparison of the results predicted using different models with the available experimental and simulated results is done. Guisbiers model is found best out of the models considered to study the band gap expansion in semiconducting nanomaterial compounds. The energy band gap shift in valence and conduction band with size is determined in nanosemiconductors.
{"title":"Energy bandgap variation in semiconductor compound nanomaterials","authors":"P. Chaturvedi, M. Goyal","doi":"10.32908/hthp.v50.861","DOIUrl":"https://doi.org/10.32908/hthp.v50.861","url":null,"abstract":"In the present work, we have used phenomological models for analyzing the impact of shape and size on energy band gap in semiconducting nanomaterial compounds. The models used presently are Qi model, Bond energy model and Guisbiers model. The extension of melting temperature expression for nanomaterials of the models considered is done and shape and size dependent expression of energy band gap is obtained. In this paper, we have taken group III-V semiconductor compound nanomaterials i.e., AlN, GaN, InN, GaAs and InAs. It is clear from the results obtained that decrease in the size of the semiconductor compound nanomaterials led to band gap expansion and this increase is significant for particle size below 5 nm. Comparison of the results predicted using different models with the available experimental and simulated results is done. Guisbiers model is found best out of the models considered to study the band gap expansion in semiconducting nanomaterial compounds. The energy band gap shift in valence and conduction band with size is determined in nanosemiconductors.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442912","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}
N. Çobanoğlu, Alper Genc, S. Korkut, Z. H. Karadeniz, M. Buschmann
The contact angle of droplets attracts attention as one of the relevant thermophysical properties describing the wettability behaviour of the fluids. The contact angle depends on the surface characteristics such as surface type and roughness as well as on the liquid type and surrounding atmosphere. This study aims to correct the error in the coefficient of the theoretical model developed for droplet shape prediction by Vafaei and Podowski [1]. The corrected model is also rearranged by non-dimensional numbers. The contact angle and the shape of water droplets for different volumes and surface types are predicted by the rearranged model and validated by experimental results. Contact angles have been over-estimated compared to experimental results because of measurement errors in geometrical parameters. It is found that the contact angle model is too sensitive to geometrical parameters. Moreover, the contact angle is found to be independent of the volume.
{"title":"Volume-independent contact angle prediction","authors":"N. Çobanoğlu, Alper Genc, S. Korkut, Z. H. Karadeniz, M. Buschmann","doi":"10.32908/hthp.v50.1021","DOIUrl":"https://doi.org/10.32908/hthp.v50.1021","url":null,"abstract":"The contact angle of droplets attracts attention as one of the relevant thermophysical properties describing the wettability behaviour of the fluids. The contact angle depends on the surface characteristics such as surface type and roughness as well as on the liquid type and surrounding atmosphere. This study aims to correct the error in the coefficient of the theoretical model developed for droplet shape prediction by Vafaei and Podowski [1]. The corrected model is also rearranged by non-dimensional numbers. The contact angle and the shape of water droplets for different volumes and surface types are predicted by the rearranged model and validated by experimental results. Contact angles have been over-estimated compared to experimental results because of measurement errors in geometrical parameters. It is found that the contact angle model is too sensitive to geometrical parameters. Moreover, the contact angle is found to be independent of the volume.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442423","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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