The present paper intends to introduce a new method for reducingbends erosion from particles impacts: the ribbed bend erosionprotection method. Ribs are evenly fixed in the range of 20 deg-80deg on the inner-wall of i...The present paper intends to introduce a new method for reducingbends erosion from particles impacts: the ribbed bend erosionprotection method. Ribs are evenly fixed in the range of 20 deg-80deg on the inner-wall of inside 90 deg bend and the bend (includingribs) is made of medium carbon steel. Three-dimensional numericalworks is performed and the result shows satisfactory agreement withthe experimental measurement. Numerical simulation studies thecharacteristics of axial gas flow along the bend and secondary flowat cross section.展开更多
When a gas expands through a convergent nozzle in which the ratio of the ambient to the stagnation pressures is higher than that of the critical one, the issuing jet from the nozzle is under-expanded. If a flat plate ...When a gas expands through a convergent nozzle in which the ratio of the ambient to the stagnation pressures is higher than that of the critical one, the issuing jet from the nozzle is under-expanded. If a flat plate is placed normal to the jet at a certain distance from the nozzle, a detached shock wave is formed at a region between the nozzle exit and the plate. In general, supersonic moist air jet technologies with non-equilibrium condensation are very often applied to industrial manufacturing processes. In spite of the importance in major characteristics of the supersonic moist air jets impinging to a solid body, its qualitative characteristics are not known satisfactorily. In the present study, the effect of the non-equilibrium condensation on the under-expanded air jet impinging on a vertical flat plate is investigated numerically in the case with non-equilibrium condensation, frequency of oscillation for the flow field becomes larger than that without the non-equilibrium condensation, and amplitudes of static pressure become small compared with those of dry air. Furthermore, the numerical results are compared with experimental ones.展开更多
基金Supported by the National Natural Science Foundation of China (No. 29876034).
文摘The present paper intends to introduce a new method for reducingbends erosion from particles impacts: the ribbed bend erosionprotection method. Ribs are evenly fixed in the range of 20 deg-80deg on the inner-wall of inside 90 deg bend and the bend (includingribs) is made of medium carbon steel. Three-dimensional numericalworks is performed and the result shows satisfactory agreement withthe experimental measurement. Numerical simulation studies thecharacteristics of axial gas flow along the bend and secondary flowat cross section.
文摘When a gas expands through a convergent nozzle in which the ratio of the ambient to the stagnation pressures is higher than that of the critical one, the issuing jet from the nozzle is under-expanded. If a flat plate is placed normal to the jet at a certain distance from the nozzle, a detached shock wave is formed at a region between the nozzle exit and the plate. In general, supersonic moist air jet technologies with non-equilibrium condensation are very often applied to industrial manufacturing processes. In spite of the importance in major characteristics of the supersonic moist air jets impinging to a solid body, its qualitative characteristics are not known satisfactorily. In the present study, the effect of the non-equilibrium condensation on the under-expanded air jet impinging on a vertical flat plate is investigated numerically in the case with non-equilibrium condensation, frequency of oscillation for the flow field becomes larger than that without the non-equilibrium condensation, and amplitudes of static pressure become small compared with those of dry air. Furthermore, the numerical results are compared with experimental ones.
