摘要
为研究不同膨胀状态下的复合结构喷管传热特性以及碳/酚醛材料耐烧蚀层的烧蚀特性,本文基于有限体积法编制了一套耦合传热程序,湍流模型采用k-ωSST模型。该程序分别采用二维轴对称N-S方程和二维轴对称热传导方程求解流体域和固体域,耦合传热通过热流密度相等、温度连续的方法实现。并结合热解动力学模型获得了碳/酚醛材料耐烧蚀层的热物性参数随温度和时间的变化关系。采用钝头碳/酚醛试件的气动加热算例验证了该程序的准确性,再对某碳/酚醛材料耐烧蚀层、碳/碳喉衬的复合结构喷管在不同膨胀状态下的传热特性进行了数值仿真研究。结果表明:在发动机工作初期,炭化层厚度沿喷管轴向分布与温度分布趋势相近,随着发动机工作时间增加,由于喉衬对碳/酚醛材料的热传导,使与喉衬交界面成为扩张段内炭化层厚度最大区域;当扩张段出现流动分离,分离点处炭化层厚度较大,之后沿轴向逐渐降低直至为零。
A conjugate heat transfer(CHT)code was developed based on the finite volume method to study the heat transfer of complex nozzle under different expansion states and ablation characteristics of carbon/phenolic material anti-ablation layer.The code solved the two-dimensional axisymmetric Navier-Stokes equation for the fluid domain and heat conduction equation for solid domain.The k-ωSST model was selected for turbulence closure.The CHT process was achieved by keeping the heat flux of each side consistent and continuous of temperature on the coupling-wall.And the variable thermal properties of carbon/phenolic material with time and temperature was obtained with pyrolysis kinetics model.After the CHT code was validated by aerodynamic heating test of blunt carbon/phenolic specimens,the simulation under different expansion states of complex nozzle with a carbon/phenolic material anti-ablation layer,C/C composite throat insert was carried out,the results indicated that the thickness of charing layer was consistent with temperature distribution in axial in the early stage of motor operation.Due to the heat transfer of the throat insert to the carbon/phenolic anti-ablation layer,the interface between the divergent section and the throat insert became the largest thickness of the charing layer in the divergent section.The thickness of charing layer increased suddenly,and then gradually decreased in the axial direction until it is zero when flow separation occurs in the nozzle.
作者
郑健
杨玉龙
薛海峰
ZHENG Jian;YANG Yulong;XUE Haifeng(School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;Nanjing Chenguang Group Co.,Ltd,Nanjing 210094,China)
出处
《弹道学报》
CSCD
北大核心
2023年第4期11-19,共9页
Journal of Ballistics
关键词
复合结构喷管
耦合传热
碳/酚醛
变热物性
体积烧蚀
complex nozzle
conjugate heat transfer
carbon-phenolic
variable thermal properties
volumetric ablatio
