ASHRAE标准8Z 1-1983的用户报告了预测结果和测量结果之间的差异， “螺旋桨风机气动激励风机振动和临界转速的动态特性测试方法/据信，这些差异与本标准在确定螺旋桨风机临界转速时未考虑离心加劲的影响有关。为了确定这是否属实，ASHRAE启动了ASHRAE研究项目RP-477，“在实际运行条件下预测螺旋桨风机振动响应的方法开发”该项目的目标是:确定并修改（如有必要）在个人微机上运行的、考虑离心硬化的商用有限元程序； 并使用（1）中确定的程序帮助解释根据ASHRAE标准87.1预测的螺旋桨风机临界转速与在模拟运行条件下在相同风机上测得的相应临界转速之间存在的差异。本文介绍了使用在一个轴上指定关键点的测得空间坐标的程序的技术基础螺旋桨风扇的扁平风扇叶片和相关的十字轴扇形部分，用于执行三种几何变换:1。在风机叶片上放置外倾角、螺钉或两者；2.扭转蜘蛛；和&生成指定数量的相同刀片。这些程序包含在一个计算机程序中，该程序生成可供商用微型计算机使用的输入源文件- 基于有限元程序，可用于对螺旋桨风机进行振动分析。引文:ASHRAE Transactions，第95卷，pt。1989年，温哥华

Discrepancies between predicted and measured results have been reported by users of ASHRAE Standard 8Z 1-1983, "Method of Testing Dynamic Characteristics of Propeller Fans-Aerodynamically Excited Fan Vibration and Critical Speeds/’ It was believed that these discrepancies were associated with the fact that the standard did not take into account the effects of centrifugal stiffening in determining propeller fan critical speeds° To determine whether this was true, ASHRAE initiated ASHRAE Re= search Project RP-477, "Development of a Method to Predict Vibration Response of Propeller Fans under Actual Operating Conditions." The objectives of this project were:Identify and modify, if necessary, a commercially available finite element program that runs on personal microcomputers and that takes into account centrifugal stiffening; andUse the program identified in (1) to help explain discrepancies that reportedly exist between propeller fan critical speeds predicted in accordance with ASHRAE Standard 87.1 and the corresponding critical speeds measured on the same fans in simulated operating conditionsThis paper presents the technical bases for procedures that use measured spatial coordinates of specified key points on one flat fan blade and associated spider sector of a propeller fan to perform three geometric transformations: 1. place a camber, a screw, or both in a fan blade; 2. twist the spider; and & generate a specified number of identical blades. The procedures were included in a computer program that generates input source files that can be used by a commercially available, microcomputer-based, finite element program that can be used to perform vibration analyses of propeller fans.