In this paper, the problem of unsteady laminar boundary-layer flow and heat transfer of a viscous income-pressible fluid over stretching sheet is studied numerically. The unsteadiness in the flow and temperature is ca...In this paper, the problem of unsteady laminar boundary-layer flow and heat transfer of a viscous income-pressible fluid over stretching sheet is studied numerically. The unsteadiness in the flow and temperature is caused by the time-dependent stretching velocity and surface temperature. A similarity transformation is used to reduce the governing boundary-layer equations to couple higher order non-linear ordinary differential equations. These equations are numerically solved using quasi-linearization technique. The effect of the governing parameters unsteadiness parameter and Prandtl number on velocity and temperature profile is discussed. Besides the numerical results for the local skin friction coefficient and local Nusselt number are presented. The computed results are compared with previously reported work.展开更多
随着热电联产(combined heat and power,CHP)元件与可再生能源的广泛应用,配电网与区域供热网之间的联系更加紧密,将热网与电网进行整体规划与建模十分重要。建立联合热-电网综合模型,并提出一种基于线性规划法的最优能量流求解算法,该...随着热电联产(combined heat and power,CHP)元件与可再生能源的广泛应用,配电网与区域供热网之间的联系更加紧密,将热网与电网进行整体规划与建模十分重要。建立联合热-电网综合模型,并提出一种基于线性规划法的最优能量流求解算法,该模型不仅适用于区域辐射状系统,还可以更广泛地应用在大规模网状多能流系统中。通过对电网、区域供热网以及它们之间的耦合元件进行网络拓扑分析,建立网络方程的基本矩阵规划及其线性能流模型。根据不同的网络拓扑结构,可以对网络系数矩阵进行快速修正,以适用所有的网络结构,显示出模型的通用性与实用性。通过将非线性、非凸集规划问题转化为线性规划问题,计算效率大大提高,并避免了传统算法无法收敛的问题。实例系统的计算与分析验证了所提方法的精确性与鲁棒性。展开更多
文摘In this paper, the problem of unsteady laminar boundary-layer flow and heat transfer of a viscous income-pressible fluid over stretching sheet is studied numerically. The unsteadiness in the flow and temperature is caused by the time-dependent stretching velocity and surface temperature. A similarity transformation is used to reduce the governing boundary-layer equations to couple higher order non-linear ordinary differential equations. These equations are numerically solved using quasi-linearization technique. The effect of the governing parameters unsteadiness parameter and Prandtl number on velocity and temperature profile is discussed. Besides the numerical results for the local skin friction coefficient and local Nusselt number are presented. The computed results are compared with previously reported work.
文摘随着热电联产(combined heat and power,CHP)元件与可再生能源的广泛应用,配电网与区域供热网之间的联系更加紧密,将热网与电网进行整体规划与建模十分重要。建立联合热-电网综合模型,并提出一种基于线性规划法的最优能量流求解算法,该模型不仅适用于区域辐射状系统,还可以更广泛地应用在大规模网状多能流系统中。通过对电网、区域供热网以及它们之间的耦合元件进行网络拓扑分析,建立网络方程的基本矩阵规划及其线性能流模型。根据不同的网络拓扑结构,可以对网络系数矩阵进行快速修正,以适用所有的网络结构,显示出模型的通用性与实用性。通过将非线性、非凸集规划问题转化为线性规划问题,计算效率大大提高,并避免了传统算法无法收敛的问题。实例系统的计算与分析验证了所提方法的精确性与鲁棒性。
