Abstract

We study heat rectification by means of application of an inhomogeneous distribution of a tensile mechanical stress in: (a) graded thermoelastic systems with constant cross section; (b) non-graded thermoelastic systems with variable cross section. In both cases the thermal conductivity of the material may be partially tuned by the internal strain produced by the application of transversal mechanical stress. We calculate the rectification coefficient $\mathrm{R}$ as function of different control parameters, such as applied strain, stoichiometry, geometry, external heat flux. In the case (a) we consider three different graduations $c={(x/L_1)}^n, n=1,2,3,$ in the case (b) three different internal strain distributions $ϵ(x)={ϵ}_0{(\frac{L_1-x}{L_1})}^n, n=1, 2, 3,$ with L₁ the length of the system and $ϵ$₀ a constant strain. In both cases we show that, the higher n, the higher the rectification coefficient. We have also considered how the rectification depends on $ϵ$₀, whose value may be easily controlled from the outside, thus allowing some degree of control on the rectification coefficient.

摘要

我们通过应用拉伸机械应力的不均匀分布来研究热整流： (a) 具有恒定横截面的渐变热弹性系统；(b) 具有可变截面的非梯度热弹性系统。在这两种情况下，材料的热导率可以通过施加横向机械应力产生的内部应变部分调整。我们计算整流系数$\mathrm{电阻}$作为不同控制参数的函数，例如施加的应变、化学计量、几何形状、外部热通量。在情况 (a) 中，我们考虑三种不同的分级$C={(X/{升}_1)}^n, n=1,2,3,$ 在情况 (b) 三种不同的内部应变分布中 $\epsilon (X)={\epsilon }_0{(\frac{{升}_1-X}{{升}_1})}^n, n=1, 2, 3,$与大号₁的系统的长度和$\epsilon$₀恒定应变。在这两种情况下，我们都表明，n越高，整流系数越高。我们也考虑了整改取决于$\epsilon$₀，其值可以很容易地从外部控制，从而允许对整流系数进行一定程度的控制。