Strojniški vestnik最新文献_第6页

Modelling of flow boiling process in small diameter tubes 小直径管内流动沸腾过程的模拟

Strojniški vestnik Pub Date : 1900-01-01 DOI: 10.1615/ICHMT.2004.INTTHERMSCISEMIN.800

D. Mikielewicz, J. Mikielewicz

引用次数: 3

Modelling of vertical wall influence on the single bubble motion 垂直壁面对单泡运动影响的模拟

Strojniški vestnik Pub Date : 1900-01-01 DOI: 10.1615/ICHMT.2004.INTTHERMSCISEMIN.750

D. Mikielewicz, J. Wajs

引用次数: 0

Heat transfer distribution for a free/porous system with forced convection and heat generation : a numerical study 具有强制对流和热生成的自由/多孔系统的传热分布:数值研究

Strojniški vestnik Pub Date : 1900-01-01 DOI: 10.1615/ICHMT.2004.INTTHERMSCISEMIN.1150

A. Sousa

引用次数: 1

Numerical study of thermal streak spacing in turbulent boundary layer with constant heat-flux boundary condition 等热流边界条件下湍流边界层热条纹间距的数值研究

Strojniški vestnik Pub Date : 1900-01-01 DOI: 10.1615/ICHMT.2000.THERSIEPROCVOL2THERSIEPROCVOL1.240

I. Tiselj, E. Pogrebnyak, A. Mosyak, G. Hetsroni

{"title":"Numerical study of thermal streak spacing in turbulent boundary layer with constant heat-flux boundary condition","authors":"I. Tiselj, E. Pogrebnyak, A. Mosyak, G. Hetsroni","doi":"10.1615/ICHMT.2000.THERSIEPROCVOL2THERSIEPROCVOL1.240","DOIUrl":"https://doi.org/10.1615/ICHMT.2000.THERSIEPROCVOL2THERSIEPROCVOL1.240","url":null,"abstract":"Direct numerical simulation (DNS) of the fully developed thermal field in a flume was performed. Constant heat flux boundary condition was imposed on the heated bottom in a way, which allowed tracing of the temperature fluctuations on the wall. Free surface boundary conditions for momentum and adiabatic boundary condition for temperature were applied on the free surface. Ill-posedness of the energy equation with such boundary conditions was removed with an additional constrain: average non-dimensional wall temperature was fixed to zero. DNS was performed at constant friction Reynolds number Re=171 and Prandtl numbers 1 and 5.4. The type of the boundary condition did not affect the profile of the mean temperature. The main difference between two types of boundary conditions is in the temperature RMS fluctuations, which retain a nonzero value on the wall for constant heat flux boundary condition, and zero for constant non-dimensional temperature. Certain changes are visible also in the behavior of skewness, flatness, and other turbulent statistics in the near-wall region. An important issue is the difference between the thermal streak spacing on the isoflux wall and the velocity streak spacing near the wall. While the thermal streaks closely follow the velocity streaks for isotemperature wall boundary condition, the temperature streaks near the isoflux wall do not coincide with the velocity low speed streaks. The DNS shows that thermal streak spacing near the wall depends on Prandtl number. Thermal streak spacing is larger than the velocity streak spacing and is approaching to the well known value of the velocity streak spacing (90-100 wall units) at Prandtl number Pr=5.4.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116216176","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}

引用次数: 2

Experimental investigation and mathematical modelling of heat transfer coefficient in double slope solar still 双斜面太阳蒸馏器传热系数的实验研究与数学建模

Strojniški vestnik Pub Date : 1900-01-01 DOI: 10.5545/SV-JME.2021.7156

R. Patel, Anshul Yadav, J. Winczek

{"title":"Experimental investigation and mathematical modelling of heat transfer coefficient in double slope solar still","authors":"R. Patel, Anshul Yadav, J. Winczek","doi":"10.5545/SV-JME.2021.7156","DOIUrl":"https://doi.org/10.5545/SV-JME.2021.7156","url":null,"abstract":"n this study, a double slope solar still has been designed and fabricated with the help of locally available materials for the climatic condition of Sultanpur, India. The experimental study was performed to investigate the effect of basin water, wind velocity on the heat transfer coefficient (convective, evaporative, and radiative) and yield of solar still. A mathematical model is developed to understand the impact of wind velocity and basin water depth in the double slope solar still on the heat transfer coefficient. It was found that the convective heat transfer coefficient depends upon the water mass and the temperature of basin mass, and glass cover temperature. The maximum value of hew (55.05 W/(m2K) and 31.80 W/(m2K)) and hcw , (2.48 W/(m2K) and 2.38 W/(m2K)) found for depths of 2 cm and 5 cm, respectively. The radiative heat transfer coefficient found to be a maximum of 8.31 W/(m2K) for 2 cm depth, and it increases as the condensation increases, because the glass surface temperature increases as vapour transfers its energy to the surface. On increasing the depth from 2 cm to 5 cm, the yield from the solar still decreases by 25.45 %. The maximum yield of 2.5 l/m2/day was found for a 2 cm water depth. The theoretical and experimental yield agreed with an error of 7.5 %, 3.25 %, 7.4 %, and 8.4 % for water depths of 2 cm, 3 cm, 4 cm, and 5 cm, respectively. It was also found that the yield from the solar still increases as the wind speed increase because this leads the faster condensation at the glass surface.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115493499","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}

引用次数: 1

Mechanical properties of adhesive joints made with pressure-sensitive adhesives 压敏胶粘剂粘接接头的力学性能

Strojniški vestnik Pub Date : 1900-01-01 DOI: 10.5545/SV-JME.2021.7253

A. Rudawská, M. Wahab

引用次数: 3

Numerical investigation on the effects of nozzle geometry on the performance of a pulse detonation engine 喷管几何形状对脉冲爆震发动机性能影响的数值研究

Strojniški vestnik Pub Date : 1900-01-01 DOI: 10.1615/ICHMT.2004.INTTHERMSCISEMIN.1020

M. Amin, Hasan Z. Rouf, J. Cambier

{"title":"Numerical investigation on the effects of nozzle geometry on the performance of a pulse detonation engine","authors":"M. Amin, Hasan Z. Rouf, J. Cambier","doi":"10.1615/ICHMT.2004.INTTHERMSCISEMIN.1020","DOIUrl":"https://doi.org/10.1615/ICHMT.2004.INTTHERMSCISEMIN.1020","url":null,"abstract":"A numerical study is presented on the effects of various nozzle geometries and operating conditions on the performance of a Pulse Detonation Engine (PDE). An unsteady numerical simulation model, which is second order accurate in space and first order accurate in time, using an automated Java based computational fluid dynamics (CFD) software is presented. One- and two-dimensional transient CFD models were employed in a systematic manner to study the propulsive performance characteristics of the PDE under different operating conditions. Preliminary studies of the effects of nozzle geometry on the performance characteristics of a generic PDE are presented. The results indicate that an expanding nozzle, capable of adapting with the cycle time and the ambient pressure, is very suitable for optimizing the PDE performance. Addition of a straight, diverging or converging nozzle improves the performance. However, it is observed that there is an optimum value of the exit area of a divergent nozzle for performance improvement. At low ambient pressure addition of a nozzle increases the specific impulse of the PDE tube. It is also seen that a diverging nozzle is more effective than a converging-diverging nozzle at low ambient pressure. The study indicates that increased volume of the reacting fuel mixture has a negative effect on the PDE performance. The results show that a 25% reduction of the reacting fuel mixture leads to approximately 18% increase in the value of the specific impulse.","PeriodicalId":237575,"journal":{"name":"Strojniški vestnik","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130437186","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}

引用次数: 3

Numerical Simulation on Mixed Convection in a Porous Medium Heated by a Vertical Cylinder 垂直圆柱加热多孔介质混合对流的数值模拟

Strojniški vestnik Pub Date : 1900-01-01 DOI: 10.1615/ICHMT.2004.INTTHERMSCISEMIN.1050

Ling Li, S. Kimura

引用次数: 3

Numerical computation of turbulent conjugate heat transfer in air heater 空气加热器湍流共轭传热的数值计算

Strojniški vestnik Pub Date : 1900-01-01 DOI: 10.1615/ICHMT.2004.INTTHERMSCISEMIN.980

M. Hriberšek, B. Širok, Z. Žunić, L. Skerget

引用次数: 5