scholarly journals Working Characteristics of a Mechanical Insufflation-Exsufflation Device

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yan Shi ◽  
Shuai Ren ◽  
Maolin Cai ◽  
Weiqing Xu
Keyword(s):  
Mathematical Model ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Ventilation System ◽  
Suction Pressure ◽  
Simulation Research ◽  
Respiratory Compliance ◽  
Set Up ◽  
The Mathematical Model ◽  
Secretion Clearance

Secretions of ventilated patients must be cleared efficiently and timely; to improve the secretion clearance efficiency of an insufflation-exsufflation device (IL-IE device) and lay a foundation for the optimization of the IL-IE device, a mathematical model of the ventilation system with the IL-IE device is set up. Through the experimental and simulation research on the ventilation system, it can be concluded that, firstly, the mathematical model is proved to be authentic and reliable. Secondly, with the deposition of secretion or an increase in the respiratory compliance, the peak exsufflation airflow may be reduced. Thirdly, with a decrease in the suction pressure, the peak exsufflation airflow of the ventilated lung may rise proportionally, but the minimum pressure in the ventilated lung may descend proportionally. To improve the efficiency of the secretion clearance but not to injure the ventilated patient, the suction pressure can be elevated properly. Last, increasing the inspiratory positive airway pressure (IPAP) is a method to improve the secretion clearance efficiency. This research lays a foundation for improving the secretion clearance efficiency of the IL-IE device.

DIMENSIONLESS OPTIMIZATION STUDY ON A VENTILATOR WITH SECRETION CLEARANCE FUNCTION

2015 ◽  
Vol 15 (03) ◽  
pp. 1550032 ◽  
Author(s):  
YAN SHI ◽  
JINGLONG NIU ◽  
MAOLIN CAI ◽  
WEIQING XU
Keyword(s):  
Mathematical Model ◽  
Simulation Study ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Ventilation System ◽  
Suction Pressure ◽  
Optimization Study ◽  
Expiratory Positive Airway Pressure ◽  
The Mathematical Model ◽  
Secretion Clearance

To improve the efficiency and safety of secretion clearance, a novel ventilator (SC ventilator) with an automatic secretion clearance function is proposed. To lay a foundation for the optimization of the SC ventilator, the basic mathematical model of the ventilation system is derived. By selecting the appropriate reference values, the basic mathematical model is transformed to a dimensionless expression for simulation. Through the experimental and simulation study on the SC ventilation system, it can be concluded that: firstly, the mathematical model is proved to be authentic and reliable. Secondly, the influences of the three key parameters on the dynamics of the SC ventilation system are carried out. Last, to guarantee the pressure in the lung is higher than the expiratory positive airway pressure, the dimensionless minimum pressure in the flexible tube should be set higher than 0.9164, the dimensionless suction pressure should be set higher than 0.79.

scholarly journals Dynamic Characteristics of Mechanical Ventilation System of Double Lungs with Bi-Level Positive Airway Pressure Model

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Dongkai Shen ◽  
Qian Zhang ◽  
Yan Shi
Keyword(s):  
Mathematical Model ◽  
Mechanical Ventilation ◽  
Dynamic Characteristics ◽  
Airway Pressure ◽  
Life Support ◽  
Positive Airway Pressure ◽  
Coupling Effect ◽  
Ventilation System ◽  
System A ◽  
Set Up

In recent studies on the dynamic characteristics of ventilation system, it was considered that human had only one lung, and the coupling effect of double lungs on the air flow can not be illustrated, which has been in regard to be vital to life support of patients. In this article, to illustrate coupling effect of double lungs on flow dynamics of mechanical ventilation system, a mathematical model of a mechanical ventilation system, which consists of double lungs and a bi-level positive airway pressure (BIPAP) controlled ventilator, was proposed. To verify the mathematical model, a prototype of BIPAP system with a double-lung simulators and a BIPAP ventilator was set up for experimental study. Lastly, the study on the influences of key parameters of BIPAP system on dynamic characteristics was carried out. The study can be referred to in the development of research on BIPAP ventilation treatment and real respiratory diagnostics.

Research on Dynamic Balance Method of Precision Centrifuge

2014 ◽  
Vol 945-949 ◽  
pp. 777-780
Author(s):  
Tao Liu ◽  
Yong Xu ◽  
Bo Yuan Mao
Keyword(s):  
Mathematical Model ◽  
Balance Control ◽  
Dynamic Balance ◽  
Dynamic Balancing ◽  
Structure Characteristics ◽  
Balance System ◽  
Simulation Results ◽  
Set Up ◽  
System Controller ◽  
The Mathematical Model

Firstly, according to the structure characteristics of precision centrifuge, the mathematical model of its dynamic balancing system was set up, and the dynamic balancing scheme of double test surfaces, double emendation surfaces were established. Then the dynamic balance system controller of precision centrifuge was designed. Simulation results show that the controller designed can completely meet the requirements of precision centrifuge dynamic balance control system.

scholarly journals Optimizing air velocity for the underfloor forced ventilation to protect a refrigerated warehouse from frost heaving

2018 ◽  
Vol 38 (3) ◽  
pp. 321-327
Author(s):  
Jingfu Jia ◽  
Manjin Hao ◽  
Jianhua Zhao
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Frost Heave ◽  
Forced Ventilation ◽  
Air Velocity ◽  
Set Up

Forced or natural ventilation is the most common measure of frost heave protection for refrigerated warehouse floor. To optimize air velocity for the underfloor forced ventilation system of refrigerated warehouse, a steady state three-dimensional mathematical model of heat transfer is set up in this paper. The temperature fields of this system are simulated and calculated by CFD software PHOENICS under different air velocity, 1.5m/s, 2.5m/s or 3.5m/s. The results show that the optimized air velocity is 1.5m/s when the tube spacing is 1.5m.

Research on Identification Model of Stator Core Temperature Rise of a Generator

2014 ◽  
Vol 1070-1072 ◽  
pp. 1216-1221
Author(s):  
Dong Xiang ◽  
Hao Xiong ◽  
Ning Bo Liu ◽  
Qiang Wu ◽  
Guang Wei Meng
Keyword(s):  
Mathematical Model ◽  
Temperature Rise ◽  
Reactive Power ◽  
Ventilation System ◽  
Stator Winding ◽  
Phase Voltage ◽  
Stator Core ◽  
Voltage Phase ◽  
The Mathematical Model ◽  
Generator Stator

This paper takes the ship air-cooled AC generator with the radial ventilation system for example, establishes the mathematical model of a generator core and winding temperature by using an equivalent thermal circuit method and the temperature calculation method based on the operating parameters, analyzes the transfer function between the generator stator winding temperature rise and the phase voltage, phase current and reactive power, and finally verifies validity of the mathematical model by the experiment.

Theoretical and Experimental Study of the Dynamics of the Tripod-Ball Sliding Joint With Clearance

2001 ◽  
Author(s):  
Jia Xiaohong ◽  
Ji Linhong ◽  
Jin Dewen ◽  
Zhang Jichuan
Keyword(s):  
Mathematical Model ◽  
Equations Of Motion ◽  
Experimental Studies ◽  
Active System ◽  
New Concepts ◽  
Sliding Joint ◽  
New Type ◽  
Set Up ◽  
The Mathematical Model ◽  
Kane Method

Abstract Clearance is inevitable in the kinematic joints of mechanisms. In this paper the dynamic behavior of a crank-slider mechanism with clearance in its tripod-ball sliding joint is investigated theoretically and experimentally. The mathematical model of this new-type joint is established, and the new concepts of basal system and active system are put forward. Based on the mode-change criterion established in this paper, the consistent equations of motion in full-scale are derived by using Kane method. The experimental rig was set up to measure the effects of the clearance on the dynamic response. Corresponding experimental studies verify the theoretical results satisfactorily. In addition, due to the nonlinear elements in the improved mathematical model of the joint with clearance, the chaotic responses are found in numerical simulation.

A Viscoelastic Model of the Neonatal Respiratory System to Assess the Efficacy of CPAP Devices

2008 ◽  
Author(s):  
Prasika I. Reddy ◽  
Ahmed M. Al-Jumaily ◽  
Geoff T. Bold
Keyword(s):  
Mathematical Model ◽  
Airway Pressure ◽  
Distress Syndrome ◽  
Positive Airway Pressure ◽  
Viscoelastic Model ◽  
Engineering Practice ◽  
Neonatal Lung ◽  
Cpap Devices ◽  
Airway Model

The objectives of this research were to; develop a validated mathematical model of the premature neonatal lung. A description of the multi-compartmental, branched airway model of the neonatal lung is presented and shown to compare well with existing in-vivo data from the literature. The model described will be used in engineering practice to assess the design of conventional and emerging forms of continuous positive airway pressure (CPAP) devices in treating respiratory distress syndrome (RDS) in premature neonates.

Numerical Analysis of Heat and Mass Transfer Performance of the Packed-Type Parallel Flow Dehumidifier

2014 ◽  
Vol 989-994 ◽  
pp. 3100-3104
Author(s):  
Rui Hang Zhang ◽  
Zi Ye Wang ◽  
Run Ping Niu
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Parallel Flow ◽  
Transfer Performance ◽  
Transfer Coefficients ◽  
Simulation Results ◽  
Set Up ◽  
The Impact ◽  
The Mathematical Model

TA mathematical model describing heat and mass transfer performance of packed-type parallel flow dehumidifier was set up. The numerical solution of differential equations was derived. Taking the heat and mass transfer coefficients obtained by experiments as the input parameters of the model, the impact of solution inlet parameters on outlet parameter of air was described. The simulation results indicated that the mathematical model could be used to predict the performance of liquid dehumidification. The results showed that the mathematical model can be of great value in the design and improvement of dehumidifier.

H∞ Robust Control for the Motion of Loader Working Device

2012 ◽  
Vol 452-453 ◽  
pp. 527-532 ◽  
Author(s):  
Wan Qiang Wang ◽  
Hui Peng Chen ◽  
Guo Jin Chen
Keyword(s):  
Mathematical Model ◽  
Robust Control ◽  
Motion Controller ◽  
Robust Controller ◽  
Simulation Research ◽  
Improve Working ◽  
Hydraulic Servo ◽  
And Performance ◽  
Set Up ◽  
Working Device

This paper has set up the electro-hydraulic servo mathematical model for loader working device and devises a device motion controller with H∞ mixed sensitivity algorithm in order to improve loader’s automaticity and maneuvering performance. This paper has done some simulation research of the servo motion controller with Matlab/Simulink. And research has shown that the H∞ robust controller may improve working device’s automaticity and maneuvering performance enormously, the device motion controller has well robust stability and performance.

scholarly journals WAVE ATTENUATION AND WAVE SET-UP ON A COASTAL REEF

1980 ◽  
Vol 1 (17) ◽  
pp. 27 ◽  
Author(s):  
Franciscus Gerritsen
Keyword(s):  
Mathematical Model ◽  
Wave Attenuation ◽  
Scale Effects ◽  
Shallow Reef ◽  
Laboratory Investigations ◽  
Deep Water Wave ◽  
Set Up ◽  
The University ◽  
Incident Waves ◽  
The Mathematical Model

In attempting to specify criteria for the design of structures on coastal reefs, it was found that no adequate method existed to derive those criteria from the deep water wave conditions. In order to fill the gap, a program of measurements and analysis was initiated at the University of Hawaii. The program consisted of prototype and laboratory measurements. Great emphasis was placed on reliable field data, which were collected on Ala Moana Reef, in Honolulu. Laboratory investigations on the behavior of waves on shallow reefs are subject to scale effects; verification from field observations is required to obtain reliable results. As a result of this study, a mathematical model was developed for the calculation of wave attenuation and wave set-up on a shallow reef, using the incident waves in the ocean as boundary conditions. This paper discusses the general behavior of waves approaching a shallow reef and presents some essential characteristics of the mathematical model. The study is limited to waves approaching the shoreline at right angles. The results of this study can be extended to breakwaters with wide, submerged berms.

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