The paper in the introductory part reviews various definitions and interpretations of structural redundancy in mechanics. The study focuses on the general structural redundancy of systems after sequences of component ...The paper in the introductory part reviews various definitions and interpretations of structural redundancy in mechanics. The study focuses on the general structural redundancy of systems after sequences of component failures followed by possible load redistributions. The second section briefly summarizes the Event Oriented System Analysis and structural redundancy in terms of the conditional probabilistic entropy. Mechanical responses to adverse loads in this approach are represented by random operational and failure events in the lifetime. The general redundancy measure in the third section of the paper employs the information entropy and goes beyond existing formulations since it includes all functional modes in service. The paper continues with a summary of traditional redundancy indices. In addition, it proposes an alternative redundancy index that accounts for the transition to secondary functional level in case of failures of primary components. The example of a ship structure illustrates the usage of the conditional entropy of subsystems of operational events and compares it to the traditional and newly proposed redundancy indices. The study at the end investigates how to enhance the safety of structures by using the redundancy based design.展开更多
The clean and efficient separation of supercritical water gasification products(SCWGP)has emerged as a significant challenge in supercritical water gasification technology.This paper proposes the use of a supersonic n...The clean and efficient separation of supercritical water gasification products(SCWGP)has emerged as a significant challenge in supercritical water gasification technology.This paper proposes the use of a supersonic nozzle for the condensation and separation of H2and CO_(2)from SCWGP,leveraging the high-pressure characteristics of these products.By establishing a flow model and a condensation model for the supersonic nozzle,the effects of inlet pressure and inlet temperature on the condensation process are analyzed.The analysis reveals that the latent heat released during condensation causes an abnormal distribution of pressure and temperature within the nozzle.When the inlet pressure of the nozzle is increased from 7.0 to 9.0 MPa,the liquid phase mass fraction at the outlet rises from 5.3×10^(-3)to 0.056.Similarly,when the inlet temperature is lowered from 300.0 to 290.0 K,the liquid phase mass fraction at the outlet also rises from 5.3×10^(-3)to 0.058.The increase in inlet pressure leads to the condensation location shifting toward the throat by~8.5×10^(-3)m·MPa^(-1),while the impact of inlet temperature is approximately-2.3×10^(-3)m·K^(-1).The nucleation rate in the nozzle is always concentrated in a small region.展开更多
文摘The paper in the introductory part reviews various definitions and interpretations of structural redundancy in mechanics. The study focuses on the general structural redundancy of systems after sequences of component failures followed by possible load redistributions. The second section briefly summarizes the Event Oriented System Analysis and structural redundancy in terms of the conditional probabilistic entropy. Mechanical responses to adverse loads in this approach are represented by random operational and failure events in the lifetime. The general redundancy measure in the third section of the paper employs the information entropy and goes beyond existing formulations since it includes all functional modes in service. The paper continues with a summary of traditional redundancy indices. In addition, it proposes an alternative redundancy index that accounts for the transition to secondary functional level in case of failures of primary components. The example of a ship structure illustrates the usage of the conditional entropy of subsystems of operational events and compares it to the traditional and newly proposed redundancy indices. The study at the end investigates how to enhance the safety of structures by using the redundancy based design.
文摘The clean and efficient separation of supercritical water gasification products(SCWGP)has emerged as a significant challenge in supercritical water gasification technology.This paper proposes the use of a supersonic nozzle for the condensation and separation of H2and CO_(2)from SCWGP,leveraging the high-pressure characteristics of these products.By establishing a flow model and a condensation model for the supersonic nozzle,the effects of inlet pressure and inlet temperature on the condensation process are analyzed.The analysis reveals that the latent heat released during condensation causes an abnormal distribution of pressure and temperature within the nozzle.When the inlet pressure of the nozzle is increased from 7.0 to 9.0 MPa,the liquid phase mass fraction at the outlet rises from 5.3×10^(-3)to 0.056.Similarly,when the inlet temperature is lowered from 300.0 to 290.0 K,the liquid phase mass fraction at the outlet also rises from 5.3×10^(-3)to 0.058.The increase in inlet pressure leads to the condensation location shifting toward the throat by~8.5×10^(-3)m·MPa^(-1),while the impact of inlet temperature is approximately-2.3×10^(-3)m·K^(-1).The nucleation rate in the nozzle is always concentrated in a small region.
