用子波分析能量最大準(zhǔn)則修正檢測(cè)壁湍流猝發(fā)的mu-level法
發(fā)布時(shí)間:2018-01-15 16:06
本文關(guān)鍵詞:用子波分析能量最大準(zhǔn)則修正檢測(cè)壁湍流猝發(fā)的mu-level法 出處:《實(shí)驗(yàn)力學(xué)》2016年02期 論文類型:期刊論文
更多相關(guān)文章: 壁湍流 猝發(fā) 速度門限法 子波分析 能量最大準(zhǔn)則
【摘要】:將壁湍流脈動(dòng)速度信號(hào)子波分析技術(shù)引入壁湍流相干結(jié)構(gòu)猝發(fā)檢測(cè)的研究,基于子波分析能量最大準(zhǔn)則確定相干結(jié)構(gòu)猝發(fā)的時(shí)間尺度,對(duì)能量最大時(shí)間尺度的子波系數(shù)進(jìn)行子波逆變換,獲得能量最大時(shí)間尺度的脈動(dòng)速度信號(hào)。根據(jù)其自相關(guān)函數(shù)的波長(zhǎng)確定相干結(jié)構(gòu)的平均猝發(fā)周期;根據(jù)能量最大時(shí)間尺度的子波系數(shù)的正極大值和負(fù)極小值檢測(cè)壁湍流噴射和掃掠事件,獲得壁湍流相干結(jié)構(gòu)噴射和掃掠事件的相位平均波形。該方法可以不需要確定門限值,有效排除了小尺度脈動(dòng)的干擾。
[Abstract]:The wavelet analysis technique of wall-turbulence pulsation velocity signal is introduced into the research of wall-turbulence coherent structure burst detection, and the time scale of coherent structure burst is determined based on the maximum energy criterion of wavelet analysis. The wavelet coefficients of the maximum energy time scale are inversely transformed to obtain the pulse velocity signal of the maximum energy time scale. The mean burst period of the coherent structure is determined according to the wavelength of the autocorrelation function. The wall turbulent jet and sweep events are detected according to the positive and negative maximum of wavelet coefficients of the maximum time scale of energy. The phase average waveforms of jet and sweep events of coherent structures with wall turbulence are obtained. The threshold value is not required and the interference of small scale pulsation can be effectively eliminated by this method.
【作者單位】: 安徽能源技術(shù)學(xué)校;天津大學(xué)力學(xué)系;
【基金】:國(guó)家自然科學(xué)基金(11272233,11332006,11572221,11411130150) 國(guó)家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(973)項(xiàng)目(No.2012CB720101,No.2012CB720103)聯(lián)合資助
【分類號(hào)】:O357.5
【正文快照】: 0引言Lu等[1]在測(cè)量近壁湍流的雷諾應(yīng)力時(shí)發(fā)現(xiàn),當(dāng)流向脈動(dòng)速度u與其均方根值u′的比值為-1時(shí),瞬時(shí)雷諾應(yīng)力具有最大值,據(jù)此,Bogard等[2]和Luchik等[3]總結(jié)出檢測(cè)壁湍流相干結(jié)構(gòu)猝發(fā)的速度門限法(u-level法)。u-level法的檢測(cè)函數(shù)定義如下:D(t)=1 u,
本文編號(hào):1429054
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