压缩性
流体动力
轴向柱塞泵
机械
体积模量
活塞(光学)
容积效率
可压缩流
带宽遏流
活塞泵
机械能
液压泵
液压油
机械工程
水力机械
控制理论(社会学)
功率(物理)
气体压缩机
热力学
工程类
物理
计算机科学
光学
人工智能
波前
控制(管理)
作者
Perry Y. Li,Jonathan Hans Barkei
标识
DOI:10.1115/fpmc2020-2801
摘要
Abstract When hydraulic fluid is compressible, the usual formula of hydraulic power being the product of pressure (p) and volumetric flow Q, which accounts only for the flow work, is not sufficient. By deriving an explicit formula for the stored compressible energy in accordance with the possibly pressure-dependent bulk modulus, a hydraulic effort (with symbol Φ) is defined to be the sum of the fluid pressure and the compressible energy density at that pressure. It is shown that Φ is the conjugate variable to volumetric flow (Q) such that that the compressible hydraulic power flow is the product Φ(p)Q. With proper understanding of compressible hydraulic power flow, the ideal relationships of pumps and motors with compressible fluid are then derived. These differ from incompressible formulae by replacing p by Φ and identifying an appropriate displacement. From these, definitions for mechanical efficiency, volumetric efficiency, and power efficiency are obtained. Unlike the previous attempts, these definitions are mutually consistent in that the product of mechanical and volumetric efficiencies is indeed the power efficiency. Furthermore, they are exact and are suitable even if the bulk modulus is pressure dependent. To gain insights into these new efficiency definitions, various modes of non-ideal effects in a piston pump/motor with variable valve timing are modeled and their effects on the mechanical, volumetric and power efficiencies are obtained. These non-ideal effects include piston-bore friction, leakage, valve throttling, and non-ideal valve timing.
科研通智能强力驱动
Strongly Powered by AbleSci AI