查询词典 pitch ratio

Pitch is a combination number of a one-to-two ratio indicating the spline proporti******; the upper or first number is the diametral pitch, the lower or second number is the stub pitch and denotes, as that fractional part of an inch, the basic radial length of engagement, both above and below the pitch circle.

径节分数：径节分数是由两个数组成的一个比率，它表示的是花键的比例；设这个比率为A/B，则在这个分数中第一个数A表示的是花键的径节，第二个数B表示的是残余径节，径节表示的是在节圆上方的键齿在半径方向上的结合长度，残余径节表示的是在节圆下方的键齿在半径方向上的结合长度。

Figure 1 the above value refers to the dot's sides and two dot pitch ratio.

图1底下的数值是指网不面的边不幼与两个网不面洋心距的比值。

The purpose of this thesis is focused on the solution of unsteady rotor/stator interaction in turbomachinery with arbitrary pitch ratio.

因此叶轮机械设计水平的提高将很大程度依赖于对其内部非定常流动的深入认识，本论文的研究工作主要针对转子和静子栅距不等时叶轮机械内部非定常流动的数值分析。

By analyzing and handling the experiments results, we obtained the rules of change of hydrodynamic characteristics of the cycloidal propeller in the pitch ratio varying from 0.2π to 0.75π and the steering angle varying from -90°to 90°, such that a foundation has been laid for using it in practice, and for setting up the theoretical calculation method of cycloidal propeller.

一、通过分析摆线推进器的工作原理，设计并加工了实验模型和实验装置，在哈尔滨工程大学船模水池对该模型进行实验，经过合理的理论分析和数据处理，获得了螺距比从0.2π到0.75π，方向角从-90°到90°范围内的水动力变化规律，为建立摆线推进器水动力性能理论计算方法和工程应用奠定了基础。

Based on Netherlands ship model Basin's open-water tests,CPP's thrust coefficients and torque coefficients in four-quadrant under different pitch ratio of screw and different types of CPP were obtained by using the method of Akima interpolation,and CPP's thrusts and torques were obtained as well.

为在船舶操纵模拟器中进行CPP船舶的操纵运动仿真，须建立其操纵运动数学模型，该模型的精度直接影响船舶操纵模拟器的逼真度。1991年，Takeda等[1]研究了CPP船舶减速时的操纵性能。1996年，Robert[2]研究了CPP船舶在不同CPP螺距和轴转速组合下的推进效率，并设计了一个鲁棒多参数推进控制系统。

The non-uniform flow behind a rigid cylinder row with a small pitch ratio T/D= 1.5 is characterized by narrow and wide near wakes and multiple frequencies, and the vortex shedding behind a rigid cylinder row with T/D= 2.0 is replicated properly by the simulation results.

此外，还研究了单列自由振动的弹性圆柱在间隙比为2.0时的流体诱导振动问题，结果表明：在大振幅条件下，流体诱导力在x方向和y方向有较强烈的耦合；随着振幅的减小，x方向振动对y方向振动的影响可以忽略，可采用单自由度的动力学模型假设进行计算。

The non-uniform flow behind a rigid cylinder row with a small pitch ratio T/D=1.5 is characterized by narrow and wide near wakes and multiple frequencies, and the vortex shedding behind a rigid cylinder row with T/D=2.0 is replicated properly by the simulation results.

计算模拟结果很好地重现了刚性单列圆柱在小间隙比(1.5)下以宽、窄尾涡交替和多频为特征的非均匀流态，以及间隙比为2.0时的涡脱落现象。

A maneuvering mathematical model for Controllable-Pitch Propeller ships with three degrees of freedom is established according to separate modeling theory. Based on Netherlands Ship Model Basin\'s open-water tests, CPP thrust coefficients and torque coefficients in four-quadrant with different pitch ratio of screw and different types of CPP are obtained by using Akima interpolation. Therefore, CPP thrusts and torques are obtained.

基于船舶操纵性分离建模理论，采用荷兰船模试验水池B系列螺旋桨的敞水试验结果，利用Akima插值获得了不同类型的调距桨在不同螺距比下的四象限推力系数和扭矩系数，求得调距桨的推力和扭矩，建立了调距桨船舶的平面运动数学模型。

Phase-lagged cyclic boundary condition is implemented by a novel method in conjunction with the developed sliding interface technique to accurately simulate the arbitrary pitch ratio rotor/stator interaction without any modifications of the physics of the problem. It's for the first time to compose the computational area into one structured grids including both rotor/stator of centrifugal or axial turbomachinery with arbitrary pitch ratio. This method can eliminate the iteration of boundary conditions on the sliding interface and calculate the unsteady flow within rotor and stator simultaneously.

为了能够在较小的计算区域内不改变叶型而真实地反映出任意栅距比时的内部非定常流场，并避免近似仍采用相位后滞周期性条件，结合本文发展的网格技术，给出了一种新的实施方法，首次将动、静叶片数不等的离心式/轴流式叶轮机械转子、静子计算区域组合在一套结构化计算网格中，动/静叶排间的滑移界面完全按内场处理，避免了每一时层内，滑移界面处边界条件的迭代计算；并保证了每一时层，滑移界面处流动参数的守恒特性。

Since the interface is treated as an internal flow field so it can accurately keep the conservation of flow variables on the sliding interface. Both laminar and turbulent unsteady rotor/stator interaction of a turbine stage with arbitrary pitch ratio are calculated successfully.

成功地计算了小雷诺数工况下具有任意栅距比的轴流动/静相干叶排内部非定常层流流动，及采用标准K-ε两方程模型对较大雷诺数工况下动/静相干轴流叶排内部非定常紊流流动进行了数值分析。

Fancy gold-plated dangling earrings with facetted White Opal crystals.

花式镀金悬垂耳环与facetted白欧泊水晶。

This essay chooses the study aim from biology teachers in middle school in Shi Jiazhuang which tells us that most of the middle school biology teachers in Shi Jiazhuang have the"burnout", lower successfulness, individualize.

本文选取石家庄市初中生物教师作为研究对象，运用问卷调查的方法对石家庄市初中生物教师职业倦怠的现状进行调查，调查结果发现，石家庄市初中生物教师这一群体普遍存在职业倦怠，情感枯竭程度偏高，成就感偏低，去个性化程度最为严重。