本研究目的在於以數值模擬方式分析FDY(Full draw Yarn)噴嘴內部流場特性,利用計算流體力學方法解析噴嘴內部三維可壓縮紊流場。本研究進行四種A、B、C、D不同型態之空氣噴嘴內部流場計算,分析不同噴嘴形態對於內部流場特性的影響,並輔以實驗數據驗證,建立高效率空氣噴嘴內部流場特性與紗支結數特性之關係式,提供空氣噴嘴對紗支結數之準確估算,並做為設計噴嘴重要參考依據。 根據實驗結果本研究發現以B、D兩型噴嘴加工之完全延伸絲的交絡特性比使用A、C兩型噴嘴加工之完全延伸絲的交絡特性為佳,而以A、C兩型噴嘴進行加工的完全延伸絲交絡特性相似,相同的特性也發生在B、D兩型噴嘴。可發現進氣管道與流道非垂直角度之空氣噴嘴對於完全延伸絲的交絡特性比進氣管道與流道垂直之空氣噴嘴具有較良好的交絡性能,因為進氣管道與流道非垂直角度之空氣噴嘴會使內部流場特性產生不對稱現象,而擴大有效交絡之範圍。
This study employs a of numerical approach to simulate the internal flow field of FDY nozzles and to correlate the interlacing characteristics of yarn processed in FDY nozzles. The three-dimensional turbulent compressible flow field inside FDY nozzles is calculated in the adopted numerical approach. Additionally the yarn interlacing characteristics of four FDY nozzles are experimentally measured. A quantitative relationship between yarn interlacing and flow field characteristics is proposed, which explains the different interlacing behaviors among four investigated FDY nozzles.