Design, Model, and Experimental Validation of a Pneumatic Boost Converter

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Tyler J. Gibson ◽  
Eric J. Barth
Keyword(s):  
Experimental Data ◽  
Dynamic Model ◽  
Experimental Validation ◽  
Boost Converter ◽  
System Efficiency ◽  
Pressure Data ◽  
Analogous System ◽  
Flow Through ◽  
Control Volumes ◽  
Experimental Pressure

This paper presents the design and dynamic model for a novel prototype pneumatic boost converter, a device developed to be an energetic equivalent to the electrical boost converter. The design of the system selects pneumatic components that are energetically equivalent to the components used in the analogous system in the electrical domain. A dynamic model for the pneumatic boost converter that describes the rapidly fluctuating pressures and volumes is developed. Movement within the system and mass flow through orifices connecting control volumes are also modeled. A prototype was developed to reclaim air at 653 kPa (80 psig) and experimental pressure data were collected at the inlet and outlet of the system. These experimental data are used to validate the dynamic model by comparing experimental and simulated pressures. The experimental data are also used to calculate the total energy reclaimed by the pneumatic boost converter as well as the system efficiency.

An Experimentally Validated Dynamic Model of the Spine

1974 ◽  
Vol 41 (3) ◽  
pp. 546-550 ◽  
Author(s):  
P. Prasad ◽  
A. I. King
Keyword(s):  
Experimental Data ◽  
Mathematical Models ◽  
Dynamic Model ◽  
Experimental Validation ◽  
Discrete Parameter ◽  
Spinal Loads ◽  
Load Transmission ◽  
Model Based ◽  
Impact Acceleration ◽  
New Feature

Although there has been a large number of mathematical models proposed for the simulation of spinal response to acceleration, few have been validated against experimental data and none appears to reflect the actual conditions of load transmission from one vertebra to the next. This paper provides a brief survey of existing spinal models and presents a discrete parameter model with experimental validation. The transmission of load via the articular facets is a major new feature of the model, based on previously obtained experimental data. Good correlation was obtained between the model results and experimentally measured spinal loads for different impact acceleration levels and spinal configurations.

Predicting Shrinkage in Semi-Crystalline Injection Mouldings – The Influence of Pressure

2006 ◽  
Vol 514-516 ◽  
pp. 1501-1505 ◽  
Author(s):  
A.J. Pontes ◽  
António Sergio Pouzada
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Pressure Data ◽  
Melt Viscosity ◽  
Effect Of Pressure ◽  
Experimental Pressure ◽  
Pressure Evolution ◽  
Good Agreement

In this study, the as-moulded shrinkage and pressure data are obtained experimentally and compared with numerical simulations. The mouldings were produced in polypropylene (PP). The effect of pressure on viscosity in the predicted pressure evolution was analyzed and also its influence on the shrinkage. The results show that the rise of holding pressure determines the reduction of the shrinkage. Also, it was observed that the pressure predictions are qualitatively in good agreement with the experimental data. However noticeable quantitative discrepancies can be observed when the effect of pressure on viscosity is not considered. If the effect of pressure on the melt viscosity is considered the deviation between predicted and the experimental pressure evolution is substantially reduced.

Comparison of Aerobic and Anoxic-Aerobic Digestion of Waste Activated Sludge

1985 ◽  
Vol 17 (8) ◽  
pp. 1475-1478 ◽  
Author(s):  
A P. C. Warner ◽  
G. A. Ekama ◽  
G v. R. Marais
Keyword(s):  
Experimental Data ◽  
Activated Sludge ◽  
Waste Activated Sludge ◽  
Activated Sludge Process ◽  
Cycle Times ◽  
Waste Sludge ◽  
Volatile Solids ◽  
In Series ◽  
Flow Through ◽  
Theoretical Simulations

The laboratory scale experimental investigation comprised a 6 day sludge age activated sludge process, the waste sludge of which was fed to a number of digesters operated as follows: single reactor flow through digesters at 4 or 6 days sludge age, under aerobic and anoxic-aerobic conditions (with 1,5 and 4 h cycle times) and 3-in-series flow through aerobic digesters each at 4 days sludge age; all digesters were fed draw-and-fill wise once per day. The general kinetic model for the aerobic activated sludge process set out by Dold et al., (1980) and extended to the anoxic-aerobic process by van Haandel et al., (1981) simulated accurately all the experimental data (Figs 1 to 4) without the need for adjusting the kinetic constants. Both theoretical simulations and experimental data indicate that (i) the rate of volatile solids destruction is not affected by the incorporation of anoxic cycles and (ii) the specific denitrification rate is independent of sludge age and is K4T = 0,046(l,029)(T-20) mgNO3-N/(mg active VSS. d) i.e. about 2/3 of that in the secondary anoxic of the single sludge activated sludge stystem. An important consequence of (i) and (ii) above is that denitrification can be integrated easily in the steady state digester model of Marais and Ekama (1976) and used for design (Warner et al., 1983).

scholarly journals Experimental Validation of Falling Liquid Film Models: Velocity Assumption and Velocity Field Comparison

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1205
Author(s):  
Ruiqi Wang ◽  
Riqiang Duan ◽  
Haijun Jia
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Velocity Field ◽  
Experimental Validation ◽  
Particle Image ◽  
Velocity Fields ◽  
Number Range ◽  
Comparison Results ◽  
Image Velocimetry ◽  
Experimental Particle

This publication focuses on the experimental validation of film models by comparing constructed and experimental velocity fields based on model and elementary experimental data. The film experiment covers Kapitza numbers Ka = 278.8 and Ka = 4538.6, a Reynolds number range of 1.6–52, and disturbance frequencies of 0, 2, 5, and 7 Hz. Compared to previous publications, the applied methodology has boundary identification procedures that are more refined and provide additional adaptive particle image velocimetry (PIV) method access to synthetic particle images. The experimental method was validated with a comparison with experimental particle image velocimetry and planar laser induced fluorescence (PIV/PLIF) results, Nusselt’s theoretical prediction, and experimental particle tracking velocimetry (PTV) results of flat steady cases, and a good continuity equation reproduction of transient cases proves the method’s fidelity. The velocity fields are reconstructed based on different film flow model velocity profile assumptions such as experimental film thickness, flow rates, and their derivatives, providing a validation method of film model by comparison between reconstructed velocity experimental data and experimental velocity data. The comparison results show that the first-order weighted residual model (WRM) and regularized model (RM) are very similar, although they may fail to predict the velocity field in rapidly changing zones such as the front of the main hump and the first capillary wave troughs.

Soft Switching Approach to Reducing Transition Losses in an On/Off Hydraulic Valve

2009 ◽  
Author(s):  
Michael B. Rannow ◽  
Perry Y. Li
Keyword(s):  
Hydraulic System ◽  
Check Valve ◽  
Fluid Flows ◽  
Soft Switching ◽  
Total System ◽  
System Efficiency ◽  
Hydraulic Systems ◽  
Controlled Systems ◽  
Flow Through ◽  
Hydraulic Valve

A method for significantly reducing the losses associated with an on/off controlled hydraulic system is proposed. There has been a growing interest in the use of on/off valves to control hydraulic systems as a means of improving system efficiency. While on/off valves are efficient when they are fully open or fully closed, a significant amount of energy can be lost in throttling as the valve transitions between the two states. A soft switching approach is proposed as a method of eliminating the majority of these transition losses. The operating principle of soft switching is that fluid can temporarily flow through a check valve or into a small chamber while valve orifices are partially closed. The fluid can then flow out of the chamber once the valve has fully transitioned. Thus, fluid flows through the valve only when it is in its most efficient fully open state. A model of the system is derived and simulated, with results indicating that the soft switching approach can reduce transition and compressibility losses by 79%, and total system losses by 66%. Design equations are also derived. The soft switching approach has the potential to improve the efficiency of on/off controlled systems and is particularly important as switching frequencies are increased. The soft switching approach will also facilitate the use of slower on/off valves for effective on/off control; in simulation, a valve with soft switching matched the efficiency an on/off valve that was 5 times faster.

Dynamic Model of Dual Clutch Lever-Based Electromechanical Actuator

2011 ◽  
Author(s):  
Vladimir Ivanovic´ ◽  
Josˇko Deur ◽  
Milan Milutinovic´ ◽  
H. Eric Tseng
Keyword(s):  
Experimental Data ◽  
Dynamic Model ◽  
Model Validation ◽  
Bond Graph ◽  
Test Rig ◽  
Electromechanical Actuator ◽  
Actuator Dynamics ◽  
Operating Modes ◽  
Graph Modeling ◽  
Bond Graph Modeling

The paper presents a dynamic model of a dual clutch lever-based electromechanical actuator. Bond graph modeling technique is used to describe the clutch actuator dynamics. The model is parameterized and thoroughly validated based on the experimental data collected by using a test rig. The model validation results are used for the purpose of analysis of the actuator behavior under typical operating modes.

scholarly journals The Design and Evaluation of a 14 Stage, 16:1 Pressure Ratio Compressor for an Industrial Gas Turbine

1996 ◽  
Author(s):  
Mohammad R. Saadatmand
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Rotor Blade ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Suction Surface ◽  
Design Intent ◽  
Flow Through ◽  
Industrial Gas Turbine

The aerodynamic design process leading to the production configuration of a 14 stage, 16:1 pressure ratio compressor for the Taurus 70 gas turbine is described. The performance of the compressor is measured and compared to the design intent. Overall compressor performance at the design condition was found to be close to design intent. Flow profiles measured by vane mounted instrumentation are presented and discussed. The flow through the first rotor blade has been modeled at different operating conditions using the Dawes (1987) three-dimensional viscous code and the results are compared to the experimental data. The CFD prediction agreed well with the experimental data across the blade span, including the pile up of the boundary layer on the corner of the hub and the suction surface. The rotor blade was also analyzed with different grid refinement and the results were compared with the test data.

scholarly journals Exact Solution for Viscoelastic Flow in Pipe and Experimental Validation

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 334
Author(s):  
Ekaterina Vachagina ◽  
Nikolay Dushin ◽  
Elvira Kutuzova ◽  
Aidar Kadyirov
Keyword(s):  
Experimental Data ◽  
Exact Solution ◽  
Analytical Methods ◽  
Experimental Validation ◽  
Parametric Method ◽  
Fluid Flows ◽  
Parametric Representation ◽  
Viscoelastic Flow ◽  
Exponential Form ◽  
Image Velocimetry

The development of analytical methods for viscoelastic fluid flows is challenging. Currently, this problem has been solved for particular cases of multimode differential rheological equations of media state (Giesekus, the exponential form of Phan-Tien-Tanner, eXtended Pom-Pom). We propose a parametric method that yields solutions without additional assumptions. The method is based on the parametric representation of the unknown velocity functions and the stress tensor components as a function of coordinate. Experimental flow visualization based on the SIV (smoke image velocimetry) method was carried out to confirm the obtained results. Compared to the Giesekus model, the experimental data are best predicted by the eXtended Pom-Pom model.

scholarly journals EXPERIMENTAL VALIDATION OF A COMPUTATIONAL PROGRAM FOR SIMULATING HYBRID SOLAR AND GAS WATER HEATING SYSTEMS

2007 ◽  
Vol 6 (2) ◽  
pp. 19
Author(s):  
J. M. S. Lafay ◽  
A. Krenzinger
Keyword(s):  
Experimental Data ◽  
Solar Energy ◽  
Computer Program ◽  
Solar Collector ◽  
Experimental Validation ◽  
Simulation Program ◽  
Water Heating ◽  
Heating Systems ◽  
Experimental Systems ◽  
Computational Program

This work presents the methodology and results of the validation of a computer program for the simulation of water heating systems combining solar energy and gas. Two experimental systems, named series and parallel, were assembled. These systems have the same components, differing on how they are connected. All the components were individually characterized and their parameters determined. Simulations of the behavior of the thermal tank, gas heater and solar collector were performed and confronted to experimental data. The results show that the simulation program “AQUESOLGAS” can accurately describe the behavior of water heating systems with solar energy and gas.

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