Dynamic Simulation of Ammonia Concentration and Emission within Swine Barns: Part I. Model Development

2010 ◽  
Vol 53 (3) ◽  
pp. 911-923 ◽  
Author(s):  
E. L. Cortus ◽  
S. P. Lemay ◽  
E. M. Barber
Keyword(s):  
Dynamic Simulation ◽  
Model Development ◽  
Ammonia Concentration ◽  
Swine Barns

Dynamic Model Development of Linear Fresnel Solar Field

2015 ◽  
Author(s):  
Elina Hakkarainen ◽  
Matti Tähtinen ◽  
Hannu Mikkonen
Keyword(s):  
Control System ◽  
Dynamic Simulation ◽  
Model Development ◽  
Control Mode ◽  
Plant Behavior ◽  
Clear Sky ◽  
Control Scheme ◽  
Control Schemes ◽  
And Control ◽  
Solar Field

As a dispatchable clean energy source, concentrated solar power (CSP) can be one of the key technologies to overcome many problems related to fossil fuel consumption and electricity balancing problems. Solar is a variable location, time and weather dependent source of energy, which sets challenges to solar field operations. With proper dynamic simulation tools it is possible to study dynamics of CSP field under changing weather conditions, find optimum control strategies, and plan and predict the performance of the field. CSP technology considered in this paper, linear Fresnel reflector (LFR), is a proven line focusing technology, having simpler design but suffering in optical performance compared to more mature parabolic trough (PT) technology. Apros dynamic simulation software is used to configure and simulate the solar field. Apros offers a possibility to dynamically simulate field behavior with varying collector configuration, field layout and control mode under varying irradiation conditions. The solar field applies recirculation (RC) as a control mode and direct steam generation (DSG) producing superheated steam. DSG sets challenges for the control scheme, which main objective is to maintain constant steam pressure and temperature at the solar field outlet under varying inlet water and energy conditions, while the steam mass flow can vary. The design and formulation of an entire linear Fresnel solar field in Apros is presented, as well as the obtained control scheme. The field includes user defined amount of collector modules, control system and two modules describing solar irradiation on the field. As two-phase water/steam flow is used, an accurate 6-equation model is used in Apros. Irradiation on the solar field under clear sky conditions is calculated according to time, position and Linke turbidity factor. Overcast conditions can be created by the clear sky index. For LFR single-axis sun tracking system is applied. In order to test the model functionality and to investigate the field behavior, thermal performance of the field was simulated at different dates at two different locations, and the results were compared. Similar field dimensions and control schemes were applied in each case, and simulations were done for full 24 hours in order to study the daily operations and ensure process stability. Control scheme functionality is evaluated based on the plant behavior in simulation cases having different operational conditions. The proper operability of the configured LFR model is evaluated. Obtained performance results show differences between locations and variation depending on season and time. The importance of a proper control system is revealed. The results show that the dynamic model development of a solar field is necessary in order to simulate plant behavior under varying irradiation conditions and to further develop optimal field control schemes and field optimizing process. The future work in the development of the LFR model presented will focus on dynamic response behavior development under transient conditions and field start-up and shut down procedure development.

An Integrated Approach for Numerical Simulation of Full Vehicle Behaviour During Transient Dynamic Maneuvers on Arbitrary Obstacles and Road Surfaces

2003 ◽  
Author(s):  
E. Duni ◽  
G. Monfrino ◽  
R. Saponaro ◽  
M. Caudano ◽  
F. Urbinati ◽  
...  
Keyword(s):  
Finite Element ◽  
Dynamic Simulation ◽  
Model Development ◽  
Integrated Approach ◽  
Element Model ◽  
Experimental Comparison ◽  
Transient Dynamic Analysis ◽  
Transient Dynamic ◽  
Full Vehicle ◽  
Stage Of Development

This work describes a numerical methodology based on the finite element method used for the transient dynamic simulation of the full vehicle rolling on different kind of obstacles. Some issues related to the tire finite element model development and its validation, by numerical-experimental comparison, have been discussed. The strategy to combine the static simulations such as the tire inflating, the vehicle weight application and suspension pre loading, with transient dynamic analysis of the car rolling over the obstacle has been chosen. The methodology, based on integration of Abaqus Implicit and Explicit codes, has been successfully applied for the dynamic simulation of Fiat Punto car passing over comfort and pothole obstacle; it is in a good stage of development for a bump obstacle (misuse airbag test).

Antecedents of learners' mental model development

2008 ◽  
Author(s):  
Nicole Kohari ◽  
Robert Lord ◽  
Joelle Elicker ◽  
Steven Ash ◽  
Bryce Hruska
Keyword(s):  
Mental Model ◽  
Model Development
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