Numerical Investigation of Turbulent Combustion during Line Heating Process

管道加热过程中湍流燃烧的数值研究

• 批准号: 12450401
• 负责人: TOMITA Yasumitsu
• 金额: $ 9.41万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12450401/
• 关键词: Line heating; Heat transfer; CFD; LIF; Combustion model; Turbulence model; 熱流動解析; 衝突噴流火炎; 乱流燃焼モデル; 火炎内温度分布; レーザ誘起蛍光法; 安全性評価; き裂損傷; 波浪荷重; 疲労強度; き裂開閉口挙動; 荷重モデル

The aim of this study is to develop a method of numerical investigation of the heat transmission from the heating gas to the plate during line-heating process.New modified-eddy-dissipation combustion model is proposed. The validity of the proposed model is demonstrated by comparing the calculated and measured gas temperature during spot heating.The transient temperature distribution is measured using a LIF apparatus in oxygen-methane gas flame from a torch moving linearly. The changing nature of temperature field during spot and line heating is investigated closely and carefully.The effectiveness of low-Reynolds number k-ε turbulence model is also investigated.As results, the followings are found ;1) From the result of L.I.F. measurement, it has been found that the relative distribution of gas temperature around the torch is almost the same as that in spot heating. It has also been found that this relative distribution is almost unchanged regardless of the temperature increase in the s … More teel plate.2) The above result leads us to a new hypothesis that the relative distributions of gas temperature and local heat transfer coefficient around the torch remain unchanged and they are almost the same as those in spot heating during line heating process. A new method of heat input estimation for line heating process based on this hypothesis, by which plate temperature distribution history can be accomplished for desired plate shape, dimensions, and torch movement history, solely from spot heating experimental results, has been propounded.3) The calculated gas temperature distribution during spot heating is in good agreement with measured one when proposed modified-eddy-dissipation combustion model is employed. It is preferable to employ the proposed model in analysis of impinging jet flame during line heating process.4) The calculation result in which low-Reynolds number k-e turbulence model is employed shows that heat flow in the immediate neighborhood of the plate surface is greatly affected by turbulent flow. This suggests that the precision of gas temperature and heat transmission calculation within the turbulent boundary layer can be improved by employing low-Reynolds number k-e turbulence model. Less

本研究的目的是发展一种数值研究水火弯板加热过程中加热气体向板材传热的方法，提出了一种新的修正涡耗散燃烧模型。通过比较点加热过程中燃气温度的计算值和实测值，验证了模型的正确性，并利用激光诱导荧光（LIF）装置测量了直线运动的氧-甲烷火焰的瞬态温度分布。本文详细研究了点加热和线加热过程中温度场的变化规律，以及低雷诺数k-ε湍流模型的有效性，结果表明：1）由L.I.F.测量结果表明，火焰周围气体温度的相对分布与点加热时基本相同。还发现，无论s中的温度增加多少，这种相对分布几乎不变。 ...更多信息 2）提出了一个新的假设，即在水火弯板加热过程中，火炬周围的气体温度和局部换热系数的相对分布保持不变，与点加热时的分布基本相同。基于这一假设，提出了一种水火弯板热输入估算的新方法，该方法仅根据现场加热实验结果，就可以得到所需板形、尺寸和焊枪运动历史的板温分布历史，3）采用修正涡激加热法，计算的局部加热时的温度分布与实测值吻合较好。采用耗散燃烧模型。采用低雷诺数k-ε湍流模型计算结果表明，湍流对平板表面附近的热流影响很大。这表明采用低雷诺数k-ε湍流模型可以提高湍流边界层内气体温度和传热计算的精度。少