An experimental investigation is described for the characteristics of convective boiling flow instabilities in horizontally helically coiled tubes using a steam-water two-phase closed circulation test loop at pressure...An experimental investigation is described for the characteristics of convective boiling flow instabilities in horizontally helically coiled tubes using a steam-water two-phase closed circulation test loop at pressure from 0.5 MPa to 3.5 MPa. Three kinds of oscillation are reported: density waves; pressure drop excursions; thermal fluctuations. We describe their dependence on main system parameters such as system pressure, mass flowrate, inlet subcooling, compressible volume and heat flux. Utilizing the experimental data together with conservation constraints, a dimensionless correlation is proposed for the occurrence of density waves.展开更多
The instability of the thermocapillary flow in liquid layers is studied in the present paper using the linear stability analysis.Based on the two-dimensional steady flow state,the three-dimensional disturbance with a ...The instability of the thermocapillary flow in liquid layers is studied in the present paper using the linear stability analysis.Based on the two-dimensional steady flow state,the three-dimensional disturbance with a wave number in the spanwise direction is considered.The effects of the aspect ratio and free surface shape of the liquid layer on the flow instability are studied,and the results are compared with the case with the two-dimensional disturbance.展开更多
文摘An experimental investigation is described for the characteristics of convective boiling flow instabilities in horizontally helically coiled tubes using a steam-water two-phase closed circulation test loop at pressure from 0.5 MPa to 3.5 MPa. Three kinds of oscillation are reported: density waves; pressure drop excursions; thermal fluctuations. We describe their dependence on main system parameters such as system pressure, mass flowrate, inlet subcooling, compressible volume and heat flux. Utilizing the experimental data together with conservation constraints, a dimensionless correlation is proposed for the occurrence of density waves.
基金supported by the National Natural Science Foundation of China (Grants No. 10872202 and 11032011)
文摘The instability of the thermocapillary flow in liquid layers is studied in the present paper using the linear stability analysis.Based on the two-dimensional steady flow state,the three-dimensional disturbance with a wave number in the spanwise direction is considered.The effects of the aspect ratio and free surface shape of the liquid layer on the flow instability are studied,and the results are compared with the case with the two-dimensional disturbance.