In this paper we carry out a numerical investigation of forced convection heat transfer from a heated elliptical cylinder in a uniform free stream with angle of inclination $\theta^{\circ}$. Numerical simulations were carried out for $10 \leq Re \leq 120$, $0^{\circ} \leq \theta \leq 180^{\circ}$, and $Pr = 0.71$. Results are reported for both steady and unsteady state regime in terms of streamlines, vorticity contours, isotherms, drag and lift coefficients, Strouhal number, and Nusselt number. In the process, we also propose a novel method of computing the Nusselt number by merely gathering flow information along the normal to the ellipse boundary. The critical $Re$ at which which flow becomes unsteady, $Re_c$ is reported for all the values of $\theta$ considered and found to be the same for $\theta$ and $180^\circ -\theta$ for $0^\circ \leq \theta \leq 90^\circ$. In the steady regime, the $Re$ at which flow separation occurs progressively decreases as $\theta$ increases. The surface averaged Nusselt number ($Nu_{\text{av}}$) increases with $Re$, whereas the drag force experienced by the cylinder decreases with $Re$. The transient regime is characterized by periodic vortex shedding, which is quantified by the Strouhal number ($St$). Vortex shedding frequency increases with $Re$ and decreases with $\theta$ for a given $Re$. $Nu_{\text{av}}$ also exhibits a time-varying oscillatory behaviour with a time period which is half the time period of vortex shedding. The amplitude of oscillation of $Nu_{\text{av}}$ increases with $\theta$.

翻译：本文对均匀来流中与加热椭圆柱成倾角θ°的强制对流传热进行了数值研究。数值模拟在10≤Re≤120、0°≤θ≤180°及Pr=0.71的条件下开展。研究结果涵盖稳态与非稳态区域，以流线、涡量等值线、等温线、阻力系数、升力系数、斯特劳哈尔数及努塞尔数的形式呈现。在此过程中，我们还提出了一种仅通过沿椭圆边界法线方向收集流动信息来计算努塞尔数的新方法。针对所有考虑的θ值，确定了流动失稳的临界Re（Rec），并发现当0°≤θ≤90°时，θ与180°-θ对应的Rec值相同。在稳态区域，随着θ增大，流动分离发生的Re逐渐降低。表面平均努塞尔数（Nuav）随Re增加而增大，而圆柱所受阻力随Re增加而减小。非稳态区域的特征为周期性涡脱落，其频率由斯特劳哈尔数（St）量化。对于给定Re，涡脱落频率随Re增大而增大，随θ增大而减小。Nuav也表现出时变振荡行为，其时间周期为涡脱落周期的一半。Nuav的振荡幅度随θ增大而增大。