Unified Numerical Analysis of Galileo Probe Entry Flight Flowfield with Radiation and Ablation

伽利略探测器进入辐射和烧蚀飞行流场的统一数值分析

• 批准号: 15560129
• 负责人: SAWADA Keisuke
• 金额: $ 2.24万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560129/
• 关键词: ablation; radiation; Galileo probe vehicle; hydrogen; multiband radiation model; recession; turbulent transition; tightly coupled calculation; ガリレオ探査衛星; マルハバンド輻射モデル

In 1995, the Galileo probe vehicle launched by NASA entered into the Jovian atmosphere at a velocity of 49 km/s. The probe vehicle was thermally protected by ablative heatshield. According to the actual flight data, the amount of heatshield recession at the stagnation point was found to be halved and that at the frustum region was doubled than those given by the preflight prediction.In this study, the strongly radiating flowfield over the Galileo probe vehicle is numerically obtained using the newly developed computer code, in which we assume the thermochemical equilibrium flowfield and also the steady ablation of the heatshield. For the first time, we have successfully reproduced the amount of heatshield recession at the frustum region. We have also identified the cause of enhanced radiative heating occurred at the frustum region. It is however indicated that the amount of heatshield recession at the stagnation region is still overestimated. This is probably caused by nonequilibrium effect in the shock layer that is not accounted for in this study. Although the nonequilibrium effect itself reduces the amount of radiative heating at the stagnation region, a more accurate prediction method is certainly needed to reduce the weight of heatshield and maximize payload in the design of future probe vehicles.As a preliminary step, we have optimized the multiband radiation model for the mixture of hydrogen and helium. At higher temperatures, the radiative property of atomic hydrogen is critically influenced by the number density of electron. Therefore, the newly developed multiband model accounts not only for the translational temperature of the gas but also for the number density of electron, simultaneously. The accuracy of the model is critically assessed. The developed radiation model will be employed in the computer simulation of nonequilibrium ionization of hydrogen observed in various shock tube experiments.

1995年，美国航天局发射的伽利略号探测器以每秒49公里的速度进入木星大气层。探测飞行器由烧蚀隔热罩进行热保护。根据实际飞行数据，发现驻点处的热屏退缩量比飞行前预测的减少了一半，而锥台区域的热屏退缩量增加了一倍。本文利用新开发的计算机程序对伽利略探测器的强辐射流场进行了数值计算，其中我们假定热化学平衡流场和隔热屏的定常烧蚀。这是第一次，我们已经成功地再现了在平截头体区域的热屏蔽衰退量。我们还确定了增强辐射加热的原因发生在锥台区域。然而，它表明，在停滞区的热屏蔽衰退量仍然是高估。这可能是由于激波层中的非平衡效应造成的，而在本研究中没有考虑到这一点。虽然非平衡效应本身减少了驻点区的辐射加热量，但在未来的探测器设计中，为了减轻隔热罩的重量并最大限度地提高有效载荷，肯定需要一种更精确的预测方法。在较高温度下，氢原子的辐射性质受电子数密度的影响很大，因此，新发展的多带模型不仅考虑了气体的平动温度，还考虑了电子数密度。该模型的准确性进行了严格的评估。所发展的辐射模型将用于各种激波管实验中观察到的氢非平衡电离的计算机模拟。

项目成果

Shinogo Matsuyama: "Parallel Computation of Fully-Coupled Hypersonic Radiating Flowfield Using Multi-Band Model"Journal of Thermophysics and Heat Transfer. 17・1. 21-28 (2003)

松山筱吾：“使用多带模型的全耦合高超声速辐射流场的并行计算”《热物理学报》17・1（2003）。

Experimental and Numerical Study of Pyrolysis Gas Pressure in Ablating Test Piece

烧蚀试件热解气体压力的实验与数值研究

• 发表时间: 2005
• 期刊: Journal of Thermophysics and Heat Transfer 19・3
• 作者: Shingo Matsuyama;Shingo Matsuyama;Shingo Matsuyama;Toshiyuki Suzuki
• 通讯作者: Toshiyuki Suzuki

Shinogo Matsuyama: "Trajectory-Based Heating Analysis of Galileo Probe Entry Flowfield with Radiation and Ablation"AIAA Paper 2003-3768. 1-10 (2003)

Shinogo Matsuyama：“伽利略探针进入流场的辐射和烧蚀基于轨迹的加热分析”AIAA 论文 2003-3768。

Multiband Radiation Model for Simulation of Galileo Probe Entry Flowfield

伽利略探测器入口流场模拟的多波段辐射模型

• 发表时间: 2006
• 期刊: Journal of Thermophysics and Heat Transfer (to appear)
• 作者: Shingo Matsuyama

Gas Permeability of Oblique-Layered Carbon-Cloth Ablator

斜层碳布烧蚀体的透气率

• 发表时间: 2004
• 期刊: Journal of Thermophysics and Heat Transfer 18・4
• 作者: Shingo Matsuyama;Shingo Matsuyama;Shingo Matsuyama;Toshiyuki Suzuki;Shingo Matsuyama;Toshiyuki Suzuki;Tohshiyuki Suzuki;Toshiyuki Suzuki
• 通讯作者: Toshiyuki Suzuki