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针对轴流压缩机叶栅内固体微粒沉积的问题,采用计算流体动力学(CFD)软件对压缩机叶栅内的气固两相流动进行了模拟。文中首先采用简单粘附模型对轴流压缩机叶栅内粒子的沉积进行了计算;在此基础上,通过引入临界速度和临界角度的概念,采用用户定义子程序发展了一种新的粒子沉积模型,简称为部分沉积模型。并将采用部分沉积模型和简单沉积模型计算得到的粒子沉积结果进行了对比,结果表明部分沉积模型得到的粒子沉积更合理。在此基础上,采用部分沉积模型预测了轴流压缩机叶栅总压损失系数随运行时间的变化和500小时后叶片壁面的压力系数分布情况。 相似文献
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带有机匣处理结构的叶栅流场数值计算 总被引:1,自引:1,他引:1
完成了一种数值计算带有机匣处理装置叶栅流动的方法。计算采用三维、非定常、可压缩N-S方程组及k-ε紊流模型方程,选择3种典型的处理结构,周向槽式机匣、轴向缝式机匣、轴向倾斜缝式机匣为算例,并引入参数周向平均的概念,以与稳态实验测量的结果做定量对比,结果发现符合较好。本文为分析机匣处理的扩稳机理提供了理论基础,也为工程设计机匣处理装置提供了新的数值工具。 相似文献
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涡轮叶栅通道内颗粒物沉积过程的数值模拟 总被引:1,自引:0,他引:1
为了更加准确获得颗粒物在涡轮中的沉积分布,以某涡轮叶片为模型,选用最接近航空发动机内部颗粒组成的Jim Bridger Power Station(JBPS)颗粒为污染物,同时,利用C++编写合适的User Defined Function(UDF)经过调试来分析颗粒沉积后叶片边界的复杂变形和边界网格依赖于时间变化的重构生成,在考虑每个时间步长颗粒沉积在叶片上从而改变叶片几何特性和换热特性的情况下,来深入研究颗粒物沉积在叶片的整个过程,最终得出了沉积的分布情况,并且通过数值研究结果与实验结果的对比,验证了网格重构与融合程序的合理性、准确性。根据叶片变形情况预测腐蚀的发生情况。随后,改变主流温度、颗粒直径来研究颗粒沉积特性。结果表明:颗粒主要沉积在叶片压力面中部,但会使得叶片前缘和压力面中部均产生明显变形;叶片前缘由于颗粒沉积使得粗糙度增加形成锯齿形,最先遭受腐蚀;颗粒直径影响颗粒沉积的分布与沉积生长速度;只影响沉积速度,并不改变沉积分布。 相似文献
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大曲率弯道和叶栅内的湍流数值模拟 总被引:3,自引:0,他引:3
本文在贴体曲线坐标系下应用非交错网格技术,发展了适于求解复杂流动的压力修正算法,采用速度的协变物理分量为动量方程的求解变量,推导得出一个适于任何曲线坐标系下控制单元体界面流通量的插值模式,可以有效地抑制不合理的波动压力场,计算表明,算法稳定收敛,计算值与试验值吻合良好,同时能预示通道内复杂的流动现象。 相似文献
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The circumferentially averaged equation of the inlet flow radial equilibrium in axial compressor was deduced.It indicates that the blade inlet radial pressure gradient is closely related to the radial component of the circumferential fluctuation (CF) source item.Several simplified cascades with/without aerodynamic loading were numerically studied to investigate the effects of blade bowing on the inlet flow radial equilibrium.A data reduction program was conducted to obtain the CF source from three-dimensional (3D) simulation results.Flow parameters at the passage inlet were focused on and each term in the radial equilibrium equation was discussed quantitatively.Results indicate that the inviscid blade force is the inducement of the inlet CF due to geometrical asymmetry.Blade bowing induces variation of the inlet CF,thus changes the radial pressure gradient and leads to flow migration before leading edge (LE) in the cascades.Positive bowing drives the inlet flow to migrate from end walls to mid-span and negative bowing turns it to the reverse direction to build a new equilibrium.In addition,comparative studies indicate that the inlet Mach number and blade loading can efficiently impact the effectiveness of blade bowing on radial equilibrium in compressor design. 相似文献
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研究了轴流压气机叶片采用非均匀栅距对叶片非定常力影响的问题,利用高分辨率格式求解准三维雷诺平均N-S方程。非定常流场计算采用了双时间步法与LU-SGS隐式解法耦合的方法。研究了带进口导叶的单级三排叶栅非定常流动,其中动叶栅距不变,而导叶和静叶采用非均匀栅距。对不同结构的计算分析表明,在导叶和静叶采用一定的非均匀栅距组合型式后,在保证压气机级的性能变化不大的同时,动叶表面所受非定常气动力的状况得到改善,这将有助于提高动叶片的疲劳寿命。 相似文献
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基于给定的进气周向总压畸变谱,应用全三维数值计算方法,研究了周向槽处理机匣对NWPU-1轴流压气机转子容畸变特性的影响,初步揭示了其在进气周向总压畸变条件下的失速机理。结果表明,在均匀进气条件下,周向槽处理机匣对叶尖间隙泄漏涡形成和发展的抑制是其扩稳的主要原因;在进气周向总压畸变条件下,该轴流压气机转子失速的主要原因是畸变引起的攻角变化,造成部分叶片的负荷过重,由于周向槽处理机匣的作用主要在叶尖部分,所以并不能有效的扩大该压气机转子的稳定工作范围。 相似文献
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轴流压气机小扰动诱发旋转失速的试验研究 总被引:1,自引:1,他引:0
为了了解压气机旋转失速产生的原因 ,用试验方法对一低速轴流压气机旋转失速前的小扰动波进行了研究 ,通过分析该扰动波的特性 ,推断出小扰动是从转子进口端壁附面层内产生的 ,该波的振荡是旋转失速产生的根源 相似文献
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This paper presents comparative numerical studies to investigate the effects of blade sweep on inlet flow in axial compressor cascades. A series of swept and straight cascades was modeled in order to obtain a general understanding of the inlet flow field that is induced by sweep.A computational fluid dynamics(CFD) package was used to simulate the cascades and obtain the required three-dimensional(3D) flow parameters. A circumferentially averaged method was introduced which provided the circumferential fluctuation(CF) terms in the momentum equation.A program for data reduction was conducted to obtain a circumferentially averaged flow field.The influences of the inlet flow fields of the cascades were studied and spanwise distributions of each term in the momentum equation were analyzed. The results indicate that blade sweep does affect inlet radial equilibrium. The characteristic of radial fluid transfer is changed and thus influencing the axial velocity distributions. The inlet flow field varies mainly due to the combined effect of the radial pressure gradient and the CF component. The axial velocity varies consistently with the incidence variation induced by the sweep, as observed in the previous literature. In addition, factors that might influence the radial equilibrium such as blade camber angles, solidity and the effect of the distance from the leading edge are also taken into consideration and comparatively analyzed. 相似文献
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