国产bbaaaaa片,成年美女黄网站色视频免费,成年黄大片,а天堂中文最新一区二区三区,成人精品视频一区二区三区尤物

首頁> 外文學(xué)位 >Combined heat and mass transfer in gas-liquid two-phase systems.
【24h】

Combined heat and mass transfer in gas-liquid two-phase systems.

機譯：氣液兩相系統(tǒng)中的傳熱和傳質(zhì)相結(jié)合。

獲取原文
獲取原文并翻譯 | 示例
  • 摘要
  • 著錄項
  • 相似文獻
  • 相關(guān)主題

摘要

Two important Processes of current interest to the safety of nuclear reactors, which involve change-of-phase in the presence of innert species in two-phase systems, were investigated.; The steady-state condensation in the presence of a noncondensable gas in a two-phase channel flow was mechanistically modeled using the two-fluid modeling technique. A flow regime map consisting of bubbly, churn-slug, and annular patterns was used, flow regime-dependent correlations for gas-liquid heat, mass and momentum transfer processes were utilized, and the effect of the noncondensable gas was accounted for using the stagnant film model. Model predictions were compared with available relevant data and indicated that the two-fluid technique along with the stagnant film model are adequate for modeling condensing two-phase channel flows with various flow patterns.; The combined heat and mass transfer during the evaporation of a superheated spherical droplet subject to an external flow field composed of its own saturated vapor, when the droplet and its surrounding vapor contain a tracer amount of a volatile transferred species, was numerically modeled. The droplet is assumed to have internal circulation similar to Hill's vortex flow. The problem is relevant to the transport of volatile radioactive material following certain nuclear reactor accidents, where the desorption rate of dissolved radionuclides need to be calculated. The droplet mass transfer model was an extension of the Kronig and Brink method to variable droplet radius, in which the transferred mass conservation equation is formulated, and numerically solved, using a coordinate system based on the streamlines defining the droplet internal circulation. Gas-side heat and mass transfer were treated using the quasi-steady film theory. Calculated parametric results, demonstrating the effects of important parameters when the partition coefficient of the transferred species is much larger than one, were performed. It was shown that the evaporation process strongly affects the transient concentration profile inside the droplet, and depending on the droplet initial superheat the average droplet concentration can increase significantly due to evaporation, before falling to the equilibrium level. Within the parameter range important to the transport of volatile radionuclides, furthermore, the species transfer process can be gas side-controlled.
機譯：研究了當(dāng)前對核反應(yīng)堆安全感興趣的兩個重要過程，它們涉及兩相系統(tǒng)中存在內(nèi)在物質(zhì)時的相變。使用兩流體建模技術(shù)對兩相通道流中存在不可凝氣體的穩(wěn)態(tài)冷凝進行了機械建模。使用由氣泡，攪動彈頭和環(huán)形模式組成的流態(tài)圖，利用氣-液熱，質(zhì)量和動量傳遞過程的流態(tài)相關(guān)性，并利用滯流來解釋不可凝氣體的影響電影模型。模型預(yù)測與可用的相關(guān)數(shù)據(jù)進行了比較，表明兩流體技術(shù)和停滯的膜模型足以用于對具有各種流型的冷凝兩相通道流進行建模。當(dāng)液滴和周圍的蒸氣中含有微量的揮發(fā)性轉(zhuǎn)移物時，在過熱的球形液滴蒸發(fā)過程中，其熱量和傳質(zhì)的結(jié)合會受到模擬，當(dāng)液滴和周圍的蒸氣中含有一定量的揮發(fā)性轉(zhuǎn)移物質(zhì)時，該過熱的球形液滴會受到由其自身飽和蒸氣組成的外部流場的影響。假定液滴具有類似于希爾渦流的內(nèi)部循環(huán)。該問題與某些核反應(yīng)堆事故之后的揮發(fā)性放射性物質(zhì)的運輸有關(guān)，在這些事故中，需要計算溶解的放射性核素的解吸速率。液滴質(zhì)量傳遞模型是Kronig和Brink方法對可變液滴半徑的擴展，其中，使用基于定義液滴內(nèi)部循環(huán)的流線的坐標系，公式化了傳遞質(zhì)量守恒方程，并對其進行了數(shù)值求解。氣態(tài)傳熱和傳質(zhì)采用準穩(wěn)態(tài)膜理論進行處理。進行了計算得出的參數(shù)結(jié)果，證明了當(dāng)轉(zhuǎn)移物種的分配系數(shù)遠大于1時重要參數(shù)的影響。結(jié)果表明，蒸發(fā)過程強烈影響液滴內(nèi)部的瞬態(tài)濃度分布，根據(jù)液滴的初始過熱度，平均液滴濃度會由于蒸發(fā)而顯著增加，然后降至平衡水平。此外，在對揮發(fā)性放射性核素的運輸很重要的參數(shù)范圍內(nèi)，可以通過氣體側(cè)控制物質(zhì)轉(zhuǎn)移過程。

著錄項

  • 作者

    Eghbali, Davoud A.;

  • 作者單位

    Georgia Institute of Technology.;

  • 授予單位 Georgia Institute of Technology.;
  • 學(xué)科 Engineering Sanitary and Municipal.; Engineering Mechanical.
  • 學(xué)位 Ph.D.
  • 年度 1997
  • 頁碼 318 p.
  • 總頁數(shù) 318
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類 建筑科學(xué);機械、儀表工業(yè);
  • 關(guān)鍵詞

相似文獻

  • 外文文獻
  • 中文文獻
  • 專利
獲取原文

客服郵箱：kefu@zhangqiaokeyan.com

京公網(wǎng)安備：11010802029741號 ICP備案號：京ICP備15016152號-6 六維聯(lián)合信息科技 (北京) 有限公司?版權(quán)所有

  • 客服微信

  • 服務(wù)號