Cubic equations of state(EOSs) are simple and easy at calculation. One way of improving the accuracy of a cubic EOS is through the modification of temperature-dependent energy parameter by using alpha-function.The ind...Cubic equations of state(EOSs) are simple and easy at calculation. One way of improving the accuracy of a cubic EOS is through the modification of temperature-dependent energy parameter by using alpha-function.The industrial applications of natural gas are very wide and as a result, prediction of thermodynamic properties and phase behavior of natural gas is an important part of design for such processes. In this work we develop a newα-function for the Peng-Robinson(PR) EOS with the parameters optimized especially for natural gas components.The parameters are generalized as a linear function of acentric factor. The results are compared to the predictions from original PR EOS and other α-functions in literature. It is shown that the new α-function presents a good accuracy with the average deviation of 1.42% for natural gas components.展开更多
The aim of this article is to provide a survey on the most popular modeling approaches for PMAs （pneumatic muscle actuators）. PMAs are highly non-linear pneumatic actuators where their elongation is proportional to ...The aim of this article is to provide a survey on the most popular modeling approaches for PMAs （pneumatic muscle actuators）. PMAs are highly non-linear pneumatic actuators where their elongation is proportional to the interval pressure. During the last decade, there has been an increase in the industrial and scientific utilization of PMAs, due to their advantages such as high strength and small weight, while various types of PMAs with different technical characteristics have appeared in the literature. This article will： （a） analyse the PMA＇s operation from a mathematical modeling perspective; （b） present their merits and drawbacks of the most common PMAs; and （c） establish the fundamental basis for developing industrial applications and conducting research in this field.展开更多
文摘Cubic equations of state(EOSs) are simple and easy at calculation. One way of improving the accuracy of a cubic EOS is through the modification of temperature-dependent energy parameter by using alpha-function.The industrial applications of natural gas are very wide and as a result, prediction of thermodynamic properties and phase behavior of natural gas is an important part of design for such processes. In this work we develop a newα-function for the Peng-Robinson(PR) EOS with the parameters optimized especially for natural gas components.The parameters are generalized as a linear function of acentric factor. The results are compared to the predictions from original PR EOS and other α-functions in literature. It is shown that the new α-function presents a good accuracy with the average deviation of 1.42% for natural gas components.
文摘The aim of this article is to provide a survey on the most popular modeling approaches for PMAs （pneumatic muscle actuators）. PMAs are highly non-linear pneumatic actuators where their elongation is proportional to the interval pressure. During the last decade, there has been an increase in the industrial and scientific utilization of PMAs, due to their advantages such as high strength and small weight, while various types of PMAs with different technical characteristics have appeared in the literature. This article will： （a） analyse the PMA＇s operation from a mathematical modeling perspective; （b） present their merits and drawbacks of the most common PMAs; and （c） establish the fundamental basis for developing industrial applications and conducting research in this field.
