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題 名 | The Near-Wake Structure and Instability Characteristics Behind a V-Gutter=V型駐燄器之近尾流場結構與不穩定特性 |
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作 者 | 趙怡欽; 呂嘉弘; | 書刊名 | 中國機械工程學刊 |
卷 期 | 18:6 1997.12[民86.12] |
頁 次 | 頁555-565 |
分類號 | 447.55 |
關鍵詞 | V型駐燄器; 近尾流場結構; 不穩定特性; Afterburner; V-gutter; Instability; Near-wake; Wake; Structure; |
語 文 | 英文(English) |
英文摘要 | 本實驗主要以研究一V型駐燄器後有關渦漩流逸機構之近尾流場結構與其不穩定特 性,V型駐燄器後之渦流現象與飛機後燃器之紊流混合與燃燒不穩定等燃燒現象有很大的關 係。由實驗可以發現其近尾流場結構可以區分為四個主要分區:靜止區,渦流捲起區,衝擊 區,回授區。渦漩流逸現象是由於上下側剪力層在衝擊區接擊而使得渦流分裂為二,一者回 授一者往下游移動而成。實驗發現回授圈是由剪力層與回授區組成而其間有8π相位匹配現 象為整體不穩定之有限循環振顫特性之表現(自行維持之振顫)。絕對不穩定幾乎與回授區 重合;渦漩流逸頻率是由在自行維持之共振區尾端即直接共振區內之最大能量振幅之橫向速 度擾動決定之。 e regions: the dead zone, the vortex roll-up region, the buffet zone, and the reversed flow zone. Vortex shedding is identified as a result of splitting of the shear layer vortex after impingement of the upper and lower shear layers in the buffet zone. A feedback loop consisting of the path along the shear layer and the reversed flow zone with a s phase-matching is identified. This phase-matching characterizes the global resonance in a limit-cycle oscillation (selfsustained oscillation). Absolute instability regions in the near wake are identified in most areas of the reversed-flow zone. The shedding frequency is identified to be the one possessing maximal energy amplitude of the transverse velocity fluctuation at the end of the self-sustained resonance region, also called the direct resonance region. |
本系統中英文摘要資訊取自各篇刊載內容。