本文選題：軸流壓氣機(jī) + 周向單槽��； 參考：《中國(guó)科學(xué)院研究生院(工程熱物理研究所)》2015年碩士論文

【摘要】：為了深入認(rèn)識(shí)周向槽位置對(duì)壓氣機(jī)失速機(jī)制的影響規(guī)律,本文針對(duì)某葉尖敏感的低速單轉(zhuǎn)子軸流壓氣機(jī)開展數(shù)值計(jì)算研究。計(jì)算與實(shí)驗(yàn)結(jié)果均表明,位于葉片弦長(zhǎng)中部的周向單槽機(jī)匣擴(kuò)穩(wěn)效果最好,位于葉片前緣下游20%-30%軸向弦長(zhǎng)位置的周向單槽機(jī)匣擴(kuò)穩(wěn)效果最差。分別采用葉頂間隙截面熵云圖和機(jī)匣壁面軸向剪切應(yīng)力識(shí)別葉頂泄漏流/主流交界面的軸向位置,并根據(jù)葉頂泄漏流/主流交界面在節(jié)流過程中主要存在兩種移動(dòng)規(guī)律和失速擾動(dòng)的周向傳播特征,將周向槽分為準(zhǔn)模態(tài)和突尖兩類機(jī)匣。對(duì)于突尖類周向槽機(jī)匣,葉頂泄漏流/主流交界面在節(jié)流過程中持續(xù)向通道上游方向移動(dòng),并在近失速工況到達(dá)葉片前緣位置；對(duì)壓氣機(jī)進(jìn)一步節(jié)流會(huì)導(dǎo)致葉頂泄漏流/主流交界面溢出葉片前緣,形成突尖型失速擾動(dòng)。對(duì)于準(zhǔn)模態(tài)類周向槽機(jī)匣,葉頂泄漏流/主流交界面在大流量工況下位于周向槽下游,并在節(jié)流過程中不斷向通道上游方向移動(dòng)；當(dāng)葉頂泄漏流/主流交界面與周向槽位置相交時(shí),其軸向位置便不再變動(dòng),而且在近失速工況仍位于葉片通道內(nèi)部并不溢出。為了理解這兩種不同的葉頂泄漏流/主流交界面的演變規(guī)律,選取位于葉片前緣下游20%軸向弦長(zhǎng)且擴(kuò)穩(wěn)效果最差的準(zhǔn)模態(tài)類單槽(簡(jiǎn)稱“前槽”)和位于葉片弦長(zhǎng)中部且擴(kuò)穩(wěn)效果最好的突尖類單槽(簡(jiǎn)稱“中槽”),對(duì)其葉頂端區(qū)的流場(chǎng)結(jié)構(gòu)進(jìn)行分析。結(jié)果表明：對(duì)于前槽機(jī)匣,葉頂泄漏流與周向槽在近失速工況下的相互作用最強(qiáng),形成強(qiáng)烈的葉頂流體噴入和噴出周向槽的現(xiàn)象。這種噴入-噴出流動(dòng)帶來了兩方面的效果：一是,噴入槽內(nèi)的流動(dòng)增加了葉片壓力面附近主流的軸向速度,抑制了葉頂泄漏流穿過周向槽從而到達(dá)葉片前緣的可能性,從而解釋了近失速工況下葉頂泄漏流/主流交界面位置不再移動(dòng)的現(xiàn)象；是,在軸向逆壓梯度作用下,向槽內(nèi)噴入-噴出的流體會(huì)在槽內(nèi)卷起逆時(shí)針的“周向槽周向渦”,葉頂間隙區(qū)域也會(huì)在該周向渦的誘導(dǎo)作用下卷起順時(shí)針的“間隙周向渦”。對(duì)于中槽機(jī)匣的近失速工況,周向槽只與葉頂泄漏流相互作用,形成較弱的噴入-噴出流動(dòng),葉頂端區(qū)的流動(dòng)結(jié)構(gòu)與光壁機(jī)匣相似。進(jìn)一步對(duì)周向單槽機(jī)匣的葉頂端區(qū)軸向動(dòng)量平衡和通道堵塞分布展開分析,認(rèn)為對(duì)于突尖類的單槽機(jī)匣,葉頂流場(chǎng)的軸向動(dòng)量是影響擴(kuò)穩(wěn)效果的主要原因。中槽機(jī)匣能夠最大程度上減弱葉頂區(qū)域間隙泄漏流和槽內(nèi)流體攜帶的負(fù)軸向動(dòng)量,抑制葉頂泄漏流/主流交界面的前移和溢出,從而實(shí)現(xiàn)擴(kuò)穩(wěn)。對(duì)于準(zhǔn)模態(tài)類的前槽機(jī)匣,間隙周向渦給葉頂流動(dòng)帶來巨大的堵塞,是導(dǎo)致壓氣機(jī)提前失速的關(guān)鍵誘因。
[Abstract]:In order to deeply understand the influence of circumferential groove position on the stall mechanism of compressor, a numerical study was carried out for a low-speed single-rotor axial compressor with sensitive blade tip. The calculated and experimental results show that the circumferential single-slot casing located in the middle of the chord length of the blade is the best, and the circumferential single-slot casing located at the downstream of the leading edge of the blade is the worst. The tip clearance cross-section entropy cloud map and casing wall axial shear stress are used to identify the axial position of the tip leakage flow / mainstream interface, respectively. According to the two main moving laws and the characteristics of circumferential propagation of stall disturbance in the throttling process of the tip leakage flow / mainstream interface, the circumferential groove is divided into two types of casing: quasi mode and sharp tip. For the circumferential groove casing, the tip leakage flow / mainstream interface continuously moves upstream in the throttling process, and reaches the leading edge of the blade in the near stall condition. Further throttling on the compressor will cause the tip leakage flow / mainstream interface to overflow the front edge of the blade and form a sharp stall disturbance. For quasi-modal circumferential groove casing, the tip leakage flow / mainstream interface is located downstream of the circumferential groove under the condition of large flow rate, and moves to the upstream direction of the channel during throttling. When the tip leakage flow / mainstream interface intersects with the circumferential groove position, the axial position does not change, and the blade channel does not overflow in the near stall condition. In order to understand the evolution of the two different tip leakage flow / mainstream interfaces, Quasimodal grooves with 20% axial chord length located downstream of the blade leading edge and the worst expansion effect ("front groove") and protruded tip grooves located in the middle of the chord length of the blade (referred to as "middle groove") are selected. The flow field structure of the top region is analyzed. The results show that the interaction between the tip leakage flow and the circumferential groove is the strongest under the near stall condition for the front groove casing, resulting in a strong phenomenon of the blade top fluid ejecting into and out of the circumferential groove. The effect of this kind of jet flow is twofold: first, the flow in the slot increases the axial velocity of the main stream near the pressure surface of the blade and inhibits the possibility of the tip leakage flowing through the circumferential groove to reach the leading edge of the blade. This explains the fact that the tip leakage flow / mainstream interface is no longer moving under near-stall conditions; that is, under the action of the axial inverse pressure gradient, the fluid ejected into the tank will roll up the "circumferential vortex" counterclockwise in the tank. The tip clearance region will also roll up the clockwise "gap circumferential vortex" under the inducement of the circumferential vortex. For the near stall condition, the circumferential groove only interacts with the leakage flow at the top of the blade, resulting in a weaker jet / ejection flow, and the flow structure of the tip of the blade is similar to that of the light wall casing. The axial momentum balance and channel blockage distribution in the tip region of the circumferential single-slot casing are further analyzed. It is considered that the axial momentum of the tip flow field is the main reason for the stability expansion of the single-slot casing. The midslot casing can reduce the gap leakage flow in the tip of the blade and the negative axial momentum carried by the fluid in the trough to the maximum extent, and restrain the forward movement and overflow of the tip leakage flow / mainstream interface, so as to realize the stability expansion. For quasi-modal front-grooved casing the annular vortex of the clearance brings huge blockage to the blade top flow which is the key cause of the compressor stall ahead of time.
【學(xué)位授予單位】：中國(guó)科學(xué)院研究生院(工程熱物理研究所)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：V233

【參考文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 王Pr臣;穩(wěn)定性調(diào)控狀態(tài)下的軸流壓氣機(jī)轉(zhuǎn)子葉頂尾跡實(shí)驗(yàn)研究[D];中國(guó)科學(xué)院研究生院（工程熱物理研究所）;2013年

，

本文編號(hào)：1849085