In the present work, a new fin shape is proposed to improve the convective heat transfer in heat sinks and to reduce their weight. The problem under consideration is a natural convection problem with air as the working fluid . Three-dimensional numerical simulations are carried out using FLUENT 19.0, to solve the continuity, momentum, turbulence, and energy equations to predict the flow and temperature field for different fins on a vertical base. Five configurations of rippling fins are considered with two aspect ratios and different heat flux inputs. The numerical results are compared to previous data available in the literature for a vertical rectangular finned plate (reference case) to validate the model. For each configuration, the heat sink temperature field and the natural convection driven air flow are discussed. The heat flux is varied from $519.396\frac{W}{m^2}$ to $4674.565\frac{W}{m^2}$. The overall thermal performance is characterized by the heat dissipation rate per unit mass. By comparison to conventional rectangular fin, the proposed fin geometry can reduce the temperature at the heat sink base by up to 18.35 K, increase the mass specific heat transfer coefficient by up to 101.41%, and decreases the thermal resistance by 9.81%. Within the scope of this study, The case with one ripple provides the best thermal performance. The results also showed that, the flow and heat transfer enhancements are a decreasing function of Rayleigh number. Overall, the heat transfer enhancement is better with rippling fins than with the rectangular fins, with a maximal mass reduction of $47\%$. The proposed models provide a practical alternative to the widely adopted plate fin heat sinks, which very promising for future thermal developments.

在目前的工作中，提出了一种新的翅片形状，以改善散热器中的对流换热并减轻其重量。正在考虑的问题是以空气为工作流体的自然对流问题。使用FLUENT 19.0进行了三维数值模拟，以求解连续性，动量，湍流和能量方程，以预测垂直基础上不同鳍片的流场和温度场。考虑了具有两种纵横比和不同热通量输入的五种波纹鳍片配置。将数值结果与文献中现有的垂直矩形翅片（参考案例）的数据进行比较，以验证模型。对于每种配置，都讨论了散热器温度场和自然对流驱动的气流。$519.396\frac{\mathrm{w\; ^}}{{米}^2}$ 至 $4674.565\frac{\mathrm{w\; ^}}{{米}^2}$。整体热性能的特征在于每单位质量的散热率。与传统的矩形散热片相比，建议的散热片几何形状可以将散热器底座的温度降低多达18.35 K，将质量比传热系数提高高达101.41％，并将热阻降低9.81％。在本研究的范围内，具有一个波纹的外壳可提供最佳的热性能。结果还表明，流动和传热的增强是瑞利数的递减函数。总体而言，波纹状翅片的传热增强效果优于矩形翅片，传热效果最大。$47％$。所提出的模型为广泛采用的板翅式散热器提供了一种实用的替代方案，这对未来的热发展非常有前途。