Development and Experimental Validation of a Compressor Dynamic Model

2004 ◽  
Vol 127 (3) ◽  
pp. 599-608 ◽  
Author(s):  
M. Venturini
Keyword(s):  
Experimental Validation ◽  
Energy Systems ◽  
Test Facility ◽  
Response Analysis ◽  
Model Parameters ◽  
Modular Model ◽  
Model Response ◽  
Dynamic Analyses ◽  
The University ◽  
And Control

In recent years, transient response analysis of energy systems is becoming more and more important in optimizing plant operation and control. Furthermore, dynamic analyses are also used to integrate steady-state diagnostic analyses, since they allow the detection of malfunctions characterized by time-dependent effects. The paper deals with the development of a nonlinear modular model for compressor dynamic simulation. After developing the compressor mathematical model through a physics-based approach (laws of conservation and thermal balances), the model is implemented through the MATLAB® SIMULINK® tool. Then, a sensitivity analysis is carried out to evaluate the influence of model parameters on the model response. Finally, the model is calibrated on a multistage axial-centrifugal small size compressor running in the test facility of the University of Ferrara (Italy) and validated through experimental data taken on the compressor under investigation.

Development and Experimental Validation of a Compressor Dynamic Model

2004 ◽  
Author(s):  
M. Venturini
Keyword(s):  
Experimental Validation ◽  
Test Facility ◽  
Response Analysis ◽  
Model Parameters ◽  
Modular Model ◽  
Multi Stage ◽  
Model Response ◽  
Dynamic Analyses ◽  
The University ◽  
And Control

In recent years, transient response analysis of energy systems is becoming more and more important in optimizing plant operation and control. Furthermore, dynamic analyses are also used to integrate steady-state diagnostic analyses, since they allow the detection of malfunctions characterized by time-dependent effects. The paper deals with the development of a non-linear modular model for compressor dynamic simulation. After developing the compressor mathematical model through a physics-based approach (laws of conservation and thermal balances), the model is implemented through the Matlab® Simulink tool. Then, a sensitivity analysis is carried out to evaluate the influence of model parameters on the model response. Finally, the model is calibrated on a multi-stage axial-centrifugal small size compressor running in the test facility of the University of Ferrara (Italy) and validated through experimental data taken on the compressor under investigation.

Altitude Test Facility Humidity Control to Generate Defined Icing Conditions

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Felix M. Barth ◽  
Stephan Staudacher ◽  
Constanze Schiewe
Keyword(s):  
Optical Measurements ◽  
Nucleation Theory ◽  
Test Facility ◽  
Classical Nucleation Theory ◽  
Model Parameters ◽  
Fundamental Part ◽  
Aerosol Particle Size ◽  
The University ◽  
Ingested Nanoparticles

Abstract In altitude test facility (ATF) operation, the requirements to control humidity to generate defined icing conditions are gaining more and more importance. In this context, the ability to predict humidity and condensation becomes a fundamental part of ATF control. For this purpose, classical nucleation theory has been applied in combination with in situ measurements to derive a model suitable to predict the onset of condensation during very low temperature ATF operation. The model parameters have been acquired inside the ATF of the University of Stuttgart downstream of its air coolers. This makes the application or assumption of generalized atmospheric aerosol data unnecessary. Polydisperse nano aerosol distributions were measured and statistically evaluated, showing that a constant distribution of nano aerosol particle size can be assumed. The composition of the ingested nanoparticles was analyzed and Arizona test dust was chosen as a valid substitute material for the application in the prediction model leading to a conservative prediction. The approach has been successfully verified using optical measurements during ATF testing. Its prediction accuracy fulfills the requirements of ATF control for a variety of icing conditions in component and engine altitude testing.

Variable Geometry and Waste-Gated Automotive Turbochargers: Measurements and Comparison of Turbine Performance

1992 ◽  
Vol 114 (3) ◽  
pp. 553-560 ◽  
Author(s):  
M. Capobianco ◽  
A. Gambarotta
Keyword(s):  
Experimental Investigation ◽  
Unsteady Flow ◽  
Transient Response ◽  
Test Facility ◽  
Variable Geometry ◽  
Flow Conditions ◽  
Turbine Performance ◽  
Variable Geometry Turbine ◽  
The University ◽  
And Control

In turbocharging automotive Diesel engines, an effective method to extend the turbine flow range and control the boost level is the use of a variable geometry turbine (VGT): This technique can be very helpful to improve the transient response of the engine and reduce exhaust emissions. In order to compare the performance of variable geometry and conventional waste-gated turbines, a thorough experimental investigation was developed on a test facility at the Department of Energetic Engineering of the University of Genoa (DINE). Two VG turbines were considered: a variable area turbine (VAT) and a variable nozzle turbine (VNT). The VG turbines were compared with a fixed geometry waste-gated turbine in both steady and unsteady flow conditions, referring to mass flow and efficiency characteristics.

The Effect of Using Flipped Classroom Model to Improve Iraqi EFL Learners’ Pronunciation in English at University Level

2020 ◽  
Vol 1 (40) ◽  
pp. 631-654
Author(s):  
Khaldoon Waleed Husam Al-Mofti
Keyword(s):  
Language Learning ◽  
Flipped Classroom ◽  
Efl Learners ◽  
English Pronunciation ◽  
Before And After ◽  
Quasi Experimental ◽  
University Level ◽  
The University ◽  
And Control ◽  
Experimental Group

For Iraqi EFL learners who are studying English pronunciation in a traditional instruction method often requires more effort and hard work. Thus, using new methods of teaching such as the flipped classroom model (FCM) is necessary to facilitate learning and improve performance. Hence, this study reports on explanatory research that investigates the effect of using the FCM in the teaching of English pronunciation for Iraqi EFL learners at the university level. The study implemented mixed research methods for data collection in a quasi-experimental analysis. Therefore, two tests were conducted on the assigned groups to measure the effect of the FCM before and after the intervention. Besides, a questionnaire and interviews were used on the experiment group students to collect data about their perceptions of the FCM. The study length (lasted)  was 15 weeks and is comprised of 60 students from the department of English, College of Arts at the University of Anbar. The students were divided into two groups, experimental, and control with 30 students in each group. The findings revealed that there was a significant statistical difference between the two groups in favour of the experimental group with better performance, indicating that the FCM has considerably assisted the Iraqi EFL learners to improve their English pronunciation. Moreover, the students expressed their positive feedback and satisfaction on the use of the FCM in their responses to the questionnaire and the interviews. As such, the current study recommends further research to study the effect of applying the FCM in areas and disciplines other than language learning.

scholarly journals Barriers to Development of an App for Improving Staff-Family Communication at Israeli Geriatric Facilities

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 192-193
Author(s):  
Rinat Cohen ◽  
Gal Maydan ◽  
Shai Brill ◽  
Jiska Cohen-Mansfield
Keyword(s):  
Mobile App ◽  
Institutional Review Boards ◽  
Staff Members ◽  
Institutional Review ◽  
Implementation Planning ◽  
Institutional Adoption ◽  
Communication Needs ◽  
The University ◽  
And Control ◽  
To Receive

Abstract Family caregivers (FCs) of institutionalized noncommunicative older persons reported multiple unmet communication needs focusing on the need to receive reliable and regular updates on the patient’s condition. We have developed a mobile app for improving communication between FCs and healthcare professionals (HPs), based on 152 interviews with FCs and 13 discussion groups with HPs from four Israeli geriatric facilities. Both parties participated in app planning, tailoring it to their needs and abilities. App use implementation encountered major obstacles including the bureaucratic process concerning signing contracts between the university and software development firms, which hindered the process for a full year; data security department required disproportionate security levels that interfered with user experience and delayed the development process; the study’s definition varied across different ethics/Helsinki committees (Institutional Review Boards; IRBs), which led to different demands, e.g., insurance for medical clinical trials although no drugs or medical device were involved; lack of cooperation by mid-level staff members despite the institutional adoption of the app project; low utilization by HPs resulted in FCs not receiving timely responses. Despite these and other obstacles, we tested app use for 15 months in one facility in a pre-post-design with intervention and control groups, and we have since begun testing it in another facility. FCs who had used the app had positive feedback and wished to continue using it. App use optimization requires implementation planning, assimilating changes in each facility’s work procedures and HP’s engagement and motivation and thus depends on institutional procedures and politics.

Comparison of Analytical and Empirical Models to Capture Variations in Off-Road Vehicle Dynamics

2005 ◽  
Author(s):  
Paul J. Pearson ◽  
David M. Bevly
Keyword(s):  
Empirical Data ◽  
Vehicle Dynamics ◽  
Experimental Validation ◽  
Inertial Sensors ◽  
Analytical Models ◽  
Control Algorithms ◽  
Model Parameters ◽  
Steering Control ◽  
Steering Angle ◽  
Yaw Rate

This paper develops two analytical models that describe the yaw dynamics of a farm tractor and can be used to design or improve steering control algorithms for the tractor. These models are verified against empirical data. The particular dynamics described are the motions from steering angle to yaw rate. A John Deere 8420 tractor, outfitted with inertial sensors and controlled through a PC-104 form factor computer, was used for experimental validation. Conditions including different implements at varying depths, as would normally be found on a farm, were tested. This paper presents the development of the analytical models, validates them against empirical data, and gives trends on how the model parameters change for different configurations.

The Problem of Energy

2014 ◽  
Vol 31 (5) ◽  
pp. 3-20 ◽  
Author(s):  
John Urry
Keyword(s):  
Social Theory ◽  
21St Century ◽  
Fossil Fuel ◽  
Energy Systems ◽  
Social Thought ◽  
Human Intervention ◽  
The West ◽  
The Past ◽  
And Control ◽  
Global Growth

Energy forms and their extensive scale are remarkably significant for the ways that societies are organized. This article shows the importance of how societies are ‘energized’ and especially the global growth of ‘fossil fuel societies’. Much social thought remains oblivious to the energy revolution realized over the past two to three centuries which set the ‘West’ onto a distinct trajectory. Energy is troubling for social thought because different energy systems with their ‘lock-ins’ are not subject to simple human intervention and control. Analyses are provided here of different fossil fuel societies, of coal and oil, with the latter enabling the liquid, mobilized 20th century. Consideration is paid to the possibilities of reducing fossil fuel dependence but it is shown how unlikely such a ‘powering down’ will be. The author demonstrates how energy is a massive problem for social theory and for 21st-century societies. Developing post-carbon theory and especially practice is far away but is especially urgent.

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