Influence of Gap Between Casing and Variable Stator Blade on Axial Compressor Performance
Influence of Gap Between Casing and Variable Stator Blade on Axial Compressor Performance
复制标题
机匣与可变定子叶片之间的间隙对轴流式压缩机性能的影响
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
M. Meyer
中科院分区：
文献类型：
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作者：
B. Ribi;M. Meyer
工业应用的轴流压缩机通常由有限的一组标准化级和壳体组装而成，以满足各种客户规格。整个压缩机的性能通常通过级叠加方法来预测，其中各个级的特性（“基本特性”）被叠加。在MAN TURBO，标准叶片类型的这些“基本特性”是通过在具有可变定子叶片的试验台上进行测量而获得的。几何形状与设计用于固定速度的压缩机中使用的几何形状相同，其中通过使用可变定子叶片获得所需的操作范围。相比之下，变速已经允许一定的操作范围，并且不需要可变静叶片。然而，固定的定子叶片在叶片和壳体之间不包括间隙。本文要解决的问题是，定子叶片和壳体之间的这种附加间隙（“定子壳体间隙”）如何影响包括转子和定子的单级的特性。为了评估各种几何参数（如定子叶片设置、弦长和间隙高度）的这种影响，采用了一种简单的一维叶尖泄漏损失评估方法，然后对其进行了修改，以描述定子壳体间隙中的损失机制。相关的机制本身和模型的校准，从全三维粘性流计算推断。这些计算是针对一个8 1/2级试验压气机进行的，首先是针对真实的结构，即，具有定子壳体间隙，然后用于没有定子壳体间隙的配置（如用于具有固定定子的压缩机）。对于前一种情况，某些空气动力学参数的测量值可作为计算流体动力学结果的检查。尽管在通过计算流体动力学进行校准的过程中遇到了一些困难，但假设的修正使得通过级叠加法预测的性能与已建压气机的测量结果之间更好地一致。Copyright © 2008 by ASME
Axial compressors for industrial application are usually assembled from a limited set of standardized stages and casings to meet the various customer specifications. The performance of the entire compressor is then often predicted by a stage stacking method where the characteristics of individual stages (“base characteristics”) are superpositioned. At MAN TURBO these “base characteristics” for a standard blade type are obtained from measurements in a test rig featuring variable stator blades. The geometry is then identical to the one used in compressors designed for fixed speed where the required operating range is obtained by the use of variable stator blades. In contrast, a variable speed already allows for a certain operating range and there is no need for variable stator blades. The fixed stator blades, however, do not include a gap between blade and casing. The question to be addressed in this paper is how this additional gap between stator blade and casing (“stator casing gap”) affects the characteristic of a single stage comprising a rotor and a stator. In order to assess this influence for a variety of geometric parameters such as stator blade settings, chord length and gap height a simple one-dimensional approach for tip leakage loss assessment was adapted and then modified in order to describe the loss mechanisms in a stator casing gap. The relevant mechanism itself and the calibration of the model were inferred from full 3D viscous flow calculations. These calculations were performed for a 8 1/2 stage test compressor, first for the true configuration, i.e., with stator casing gap, and then for a configuration without stator casing gap (as used for compressors with fixed stators). For the former case measurements of some aerodynamic parameters served as check for the CFD results. Despite some difficulties encountered during the calibration by means of CFD, the postulated correction led to a better agreement between the predicted performance by the stage stacking method and the measurements of built compressors.Copyright © 2008 by ASME