共查询到18条相似文献,搜索用时 93 毫秒
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本文主要研究一种梯度响应面模型及其在气动优化设计中的应用. 目前应用广泛的多项式响应面模型是连续可导的, 采用梯度信息构造完全二阶多项式响应面模型, 所需样本数与设计参数个数呈线性关系. 首先通过改进实验设计方法, 快速生成满足精度要求的样本并确定梯度响应面模型. 随后通过函数实验验证梯度响应面模型的精度, 及该模型在多极值函数最值搜索中的有效性. 最后由伴随方法快速求解气动优化设计目标函数的梯度信息, 并开展基于梯度响应面模型和复合形法的叶片压力反设计和效率优化设计. 结果表明: 基于梯度响应面模型的优化方法在全局最优及提高优化效率两方面均有出色表现, 基于该优化方法的气动优化设计能够显著改善叶片的气动性能.
关键词:
气动优化设计
响应面模型
伴随方法
复合形法 相似文献
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叶轮机械内的三元流动解法——“流面坐标”迭代法 总被引:3,自引:0,他引:3
从吴仲华教授最早提出的两类流面交叉求解三元流动的理论出发,本文给出一种任意通流截面上的“流面坐标”迭代法,采用适合各类叶轮机械的两组非正交流面坐标,以及沿这两组坐标方向速度梯度方程的迭代求解,得到了叶轮机械内部的完全三元流场。 计算实例给出了均为扭曲的两类流面形状,并与普通的二元流面解进行了比较,在一个试验过的离心压气机叶轮的计算中还与测量结果进行了比较,结果是满意的. 相似文献
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一、前言 叶轮机械三元流动通用理论提出的使用两类流面迭代求解叶轮机械三元流动正反问题的方法,已成为内流数值计算的一个基本方法。随着计算机速度的提高、内存的扩大,越来越多的三元直接解投入了使用。但是两类流面迭代求解仍然是叶轮机械内流计算的一个重要方法。 相似文献
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基于遗传算法和逐次序列二次规划的叶栅基迭优化 总被引:9,自引:1,他引:8
本文提出并实现了一种叶轮机械全三维优化设计体系。该组合优化方案基于遗传算法(GA)进行全局搜索,响应面(RSM)近似建模和逐次序列规划(SQP)局部寻优,采用高阶非均匀有理B样条进行三维叶片参数化造型和高精度、高分辨率Navier-Stokes求解程序进行粘性流场数值模拟。通过对一低展弦比大折转角的透平环形叶栅进行基迭优化,结果表明该组合优化方案具有很好的效率、可靠性和全局搜索能力。 相似文献
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The objective of the study is to find the tolerance on vane pitch dimensions of a Vertical Turbine (VT) pump impeller. For this purpose, the study is divided into two parts viz. to find the critical hydraulic eccentricity of a VT pump impeller by way of numerical simulations and design of experiments to find the vane pitch tolerance using critical hydraulic eccentricity. The effect of impeller vane pitch deviations on hydraulic unbalance is examined for a vertical turbine pump using Design of Experiments (DOE). A suitable orthogonal matrix has been selected with vane pitch at different axial locations of an impeller as the control factors. Hydraulic eccentricity, which is the output of the DOE experiments is analyzed using S/N ratio, ANOM and regression analysis to find the significant control factor effecting the hydraulic unbalance and hence vibrations. The vane pitch deviation at outlet and inlet of impeller shroud geometry are found to be the most critical factor affecting the pump vibrations. 相似文献
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The diffractive optical element (DOE) is widely used to generate various illumination modes in the projection lithography system. The working principle and design methods of the DOE are discussed in detail in this paper. A mixed multi-region design method is proposed to calculate the phase of DOE based on the poor spatial coherence of excimer laser, using the Gerchberg–Saxton (GS) algorithm. The DOEs generating circular, dipole and quadrupole illumination modes are designed and simulated by three different methods: single region design, repeated multi-region design and mixed multi-region design. The performance of these DOEs are compared and analyzed with these three design methods. The mixed multi-region design method is used to design the DOEs generating three illumination modes, the diffraction efficiencies are greater than 85%, and the non-uniformities of illumination are less than 3%. The analysis results indicate that the DOE designed by the mixed multi-region design can achieve higher diffraction efficiency and illumination uniformity of the far-field intensity distribution without modifying the GS algorithm. 相似文献
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依托两区模型开展了单级斜流/离心压缩机的初步设计和分析方法研究,验证了基于SOA-TEIS混合扩压度模型的改进ODP问题迭代方法在斜流/离心压缩机初步设计和分析中的准确性。采用本文方法对Krain高比转速叶轮和低比转速叶轮模型进行了一维设计和分析,并将结果与实验数据进行了对比,结果表明:本文所述方法可在减少对工程经验参数选取依赖性的同时,实现较准确的斜流/离心压缩机的初步设计计算和非设计工况性能预测,且易于程序化实现,采用被动滑移因子计算方法获得的设计点附近工况的等熵效率预测偏差在1%以内。 相似文献
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Ameya M. Mahadeshwar Sangram S. Patil Vishwadeep C. Handikherkar Vikas M. Phalle 《声与振动》2018,52(5):12-21
Wide range of rotating machinery contains an inherent amount of unbalance which leads to increase in the vibration level and related faults. In this work, the effect of different operating conditions viz. the unbalanced weight, radius, speed and position of the rotor disc on the unbalance in rotating machine are studied experimentally and analyzed by using Response Surface Methodology (RSM). RSM is a technique which consists of mathematical and statistical methods to develop the relationship between the inputs and outputs of a system by distinct functions. L27 Orthogonal Array (OA) was developed by using Design of Experiments (DOE) according to which experimentation has been carried out. Three accelerometer sensors were mounted to record the vibration responses (accelerations) in radially vertical, horizontal and axial directions. The responses recorded as root mean square values are then analysed using RSM. The relationship between response and operating factors has been established by developing a second order, non-linear mathematical model. Analysis of variance (ANOVA) has been performed for verification of the developed mathematical models. Results obtained from the analysis show that the unbalance weight and speed are most significant operating conditions that contribute the most to the effect the unbalance has on the rotating spindle. 相似文献