Large flow rate/high frequency microvalve array for high performance actuators

The fabrication, analysis, and testing of a large flow rate and high frequency microvalve array are presented in this paper. The array consists of 88-microvalves fabricated on a silicon-on-insulator (SOI) substrate. The SOI wafer simplifies the fabrication process and eliminates the need for multi-layer surface micromachining process and bulk wafer-bonding procedures. The analytical resonant frequency of the valve is up to 50 kHz and operates at high delta pressures (i.e. 0.14 MPa). The microvalves are fabricated with various flap widths ranging from 300 to 400 μm and flap thickness ranging from 10 to 13 μm. The results indicate that flap displacement and flow rate are strongly dependent on flap thicknesses and to a lesser degree on flap widths increases. The resonance frequency with valve flap thickness increases and width decreases. Comparison between predicted and measured flow rate shows good agreement. A flow rate up to 35 cc/sec was measured. A failure criterion is also presented using the fracture stress analysis and shows good agreement with experimental result.

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Investigation of Speed Matching Affecting Contrarotating Fan’s Performance Using Wireless Sensor Network including Big Data and Numerical Simulation

Complexity ◽

10.1155/2018/1246381 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Hengxuan Luan ◽

Liyuan Weng ◽

Ranhui Liu ◽

Yuanzhong Luan ◽

Dongmin Li

Keyword(s):

Big Data ◽

Numerical Method ◽

Flow Rate ◽

Rate Condition ◽

Small Flow Rate ◽

Large Flow Rate ◽

Small Flow ◽

Power Capability ◽

Two Stages ◽

Large Flow

This paper describes the investigations performed to better understand two-stage rotor speed matching in a contrarotating fan. In addition, this study develops a comprehensive measuring and communication system for a contrarotating fan using ZigBee network. The investigation method is based on three-dimensional RANS simulations; the RANS equations are solved by the numerical method in conjunction with a SST turbulence model. A wireless measurement system using big data method is first designed, and then a comparison is done with experimental measurements to outline the capacity of the numerical method. The results show that when contrarotating fan worked under designed speed, performance of two-stages rotors could not be matched as the designed working condition was deviated. Rotor 1 had huge influences on flow rate characteristics of a contrarotating fan. Rotor 2 was influenced by flow rates significantly. Under large flow rate condition, the power capability of rotor 2 became very weak; under working small flow rate condition, overloading would take place to class II motor. In order to solve the performance mismatch between two stages of CRF under nondesigned working conditions, under small flow rate condition, the priority shall be given to increase of the speed of rotor 1, while the speed of rotor 2 shall be reduced appropriately; under large flow rate condition, the speed of rotor 1 shall be reduced and the speed of rotor 2 shall be increased at the same time.

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