Ali Mohammad, Nasrin R, Alim M A
Department of Mathematics, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh.
Department of Mathematics, Chittagong University of Engineering and Technology, Chittagong, 4349, Bangladesh.
Heliyon. 2023 Feb 13;9(3):e13671. doi: 10.1016/j.heliyon.2023.e13671. eCollection 2023 Mar.
The slip flow and thermal transfer inside the boundary layer are extremely significant for various problems in aerodynamics, wing stall, skin friction drag on an entity, high-level velocity aircraft, etc. The current research investigated the effect of the slip factor and shape factor on the axisymmetric bullet-shaped object by taking the viscous dissipation parameter and location parameter. The analysis is conducted for both fixed and moving bullet-shaped objects due to thinner and thicker surfaces. The governing equations are transformed into a system of ordinary differential equations using suitable local axisymmetric similarity transformations and solved by applying the spectral quasi-linearization method. A new correlation analysis is made for velocity and temperature gradients. It is observed that the boundary layer structure has no defined shape due to a thicker bullet-shaped object instead it forms a steep angle with the axis which is contradictory to the formation of the boundary layer. A negative correlation is observed for the parameters , Ec, , and but a positive correlation is observed for the parameters such as , , , and . The surface thickness and stretching ratio significantly affect the fluid flow and heat transfer processes. It is also noticed that the thinner bullet-shaped object performs as a better cooling conductor compared to a thicker one. The skin friction is reduced in the case of a thinner bullet-shaped object compared to a thicker one. The present analysis reveals that the heat transfer rate and the friction factor may be helpful in industrial sectors for controlling the cooling rate and quality of the final product. This research brings forward to increase in the rate of heat transfer inside the boundary layer region. The result may help to design the various types of moving objects in the automobile engineering sector when the objects pass through the fluid.
边界层内的滑移流动和热传递对于空气动力学、机翼失速、实体表面摩擦阻力、高速飞行器等各种问题极为重要。当前的研究通过考虑粘性耗散参数和位置参数，研究了滑移因子和形状因子对轴对称子弹形物体的影响。针对表面较薄和较厚的固定和移动子弹形物体进行了分析。利用合适的局部轴对称相似变换将控制方程转化为常微分方程组，并应用谱拟线性化方法求解。对速度和温度梯度进行了新的相关性分析。观察到，由于子弹形物体较厚，边界层结构没有确定的形状，而是与轴线形成一个陡峭的角度，这与边界层的形成相矛盾。观察到参数Ec等呈负相关，但参数等呈正相关。表面厚度和拉伸比对流体流动和传热过程有显著影响。还注意到，与较厚的子弹形物体相比，较薄的子弹形物体作为更好的冷却导体。与较厚的子弹形物体相比，较薄的子弹形物体的表面摩擦减小。目前的分析表明，传热速率和摩擦系数可能有助于工业部门控制最终产品的冷却速率和质量。这项研究提出了提高边界层区域内的传热速率。当物体在流体中运动时，该结果可能有助于汽车工程领域设计各种类型的移动物体。
