Company Details Company:. Update This Listing. Media Get Started. Mit einem Experten sprechen. Platforms Windows. Type of Training Documentation. Live Online. In Person. Customer Support Business Hours. Simulation Software 1D Simulation. Agent-Based Modeling. Continuous Modeling. Design Analysis. Direct Manipulation. Discrete Event Modeling. In Ventity, you can introduce new entities on the fly during a simulation.
You can introduce them via data, or programatically with discrete Actions. Simulate and review just your real behavior, without lots of clutter. The Ventity 4.
The primary feature enhancements are to Process List actions, making it easier to restrict the number of iterations, and much faster to make small randomized selections from large entity collections. Set the entire airflow to a mixed concentration. All airflow travelling past this point will be set to the specified concentration.
This value could be derived from measured data underground, or through theoretical analysis. All simulated airflows downstream from this point will be derived from this source. Unlike general contaminant simulation, gas passing a set source will not accumulate from upstream or recirculation sources use Method 2 if this is required. Inject a pure concentration of gas into an airway, and allow it to mix with the airflow in the main airway.
Downstream from the injection point, the mixture will show the diluted levels of gas. To gain a more reasonable colour scale, the legend scale may have to be renumbered to show only the concentration of interest. To utilize this feature, ensure that Natural Ventilation is enabled, and the Gas Density option in the Air Simulation Settings is turned on. Gas distributions through pipes can be done is a similar way.
A lesson on using this method will be included in a future tutorial. To get the most out of fan simulation however, consider entering the additional optional information for more accurate results. When placing a fan in a ventilation model, use the EDIT command to specify the fan configuration. Note that options are also available to adjust the fan speed a facility available on many new variable speed fans for increasing or decreasing performance. When assessing fan performance, ensure that the operating point of the fan does not exceed the maximum stall pressure.
Fan performance and airflow in real terms will dramatically decrease, and fan life may be decreased. Try to design ventilation simulations well below this stall point to allow for some contingency in real life fan pressures. Also ensure fans are not operated below the minimum low or negated specified fan curve pressure.
While fans in real terms will still operate, power efficiency is likely to be poor, and some fan designs produce excessive vibration or blade stress. Choose a fan more suitable for this pressure duty if possible. Custom Icons are a great way to more clearly show ventilation infrastructure icons or equipment within your ventilation model.
Standard fans, resistances and heat preset items can be changed to any picture by simply dragging a picture file on to the icon. To do this, follow these simple steps. Using this option, pictures of actual ventilation fans, door, wall, regulators, and machines can be placed in your model.
Older computers with limited graphics cards or extremely large models can slow down display of graphics. Some hints to improve speed are:. Modern Graphics systems can be broadly grouped into two categories. If you are purchasing a new computer, it is recommended that a dedicated graphics card from NVidia or ATI be specified, or one of the new generation Core i3, i5 or i7 processor computers.
These days there is very little cost premium to purchase a computer with faster graphics. Dynamic Contaminants offer a way to simulate the second-by-second spread of a contaminant through a mine. Importantly, it can be dynamically changed during simulation for example doors opened or close, fans turned off, on or reversed. This means that for example emergency procedures can be performed in the simulation at any time into the dynamic simulation to see the effect of the changes to the existing spread of the contaminants.
To set a dynamic contaminant, simply use the SMOKE button to place a contaminant and then use the EDIT function to change the concentration, type and length of time the contaminant is emitted for. Other more complex options exist to reduce concentration over time, or to simulate explosive quantities.
The model can be rotated at any time during simulation, and colours of contaminant levels adjusted through the color menu if required. If a change is to be made to the circuit, the simulation can be paused at any time, and the following steps taken:. This option can be performed multiple times during simulation, and an idea of the effect of the changes can be quickly gained.
Recirculation can be defined as any portion of mine airflow that travels through the same location more than once. This function provides essential information on portions of the mine that may have controlled or uncontrolled recirculation, and allows users to gauge the potential impact and consequences of such recirculation.
To activate the recirculation function, as before simply press the recirculation button to instantly show the results.
For large models with significant recirculation, a warning may show indicating the process may take a little time to calculate. The colours will automatically change to display recirculation percentage. This design shows unacceptable recirculation levels in a ramp design. Without an accurate representation of current conditions, future design using the model will not be accurate and could provide misleading or incorrect results.
For this reason, validating your model with current actual ventilation data and conditions is very important. There is no correct answer, but every engineer and consultant should have a target to aim for based on what the model is required for.
A model that is to be used to predict future expensive infrastructure and fans should target a higher accuracy than perhaps a long term life of mine draft. Accuracy represents the difference between modelled airflows and pressures, and the actual measured airflows and pressures. Unfortunately the airway sizes, friction factors, shock losses and fan performances are often not exactly known and can be difficult or time consuming to measure in some areas.
For that reason, engineers will often use standard design sizes and default friction factors and shock losses to design a model. The notes can then be compared side-by-side with the simulated results, showing any discrepancies. This will show discrepancies in design sizes and airway locations that may warrant further investigation.
At other times, equipment moving about, doors opening or shutting, and other temporary mine disturbances can effect airflow measurements. Provided the simulation is performing without errors or warnings, it is almost certainly simply returning the results of the input data placed within the model. Work backwards from the main airflows to the surface and try to discover the discrepancy between the data put into the model such as airway sizes, frictions factors, regulators or doors, fans etc , and the actual data of the mine.
Some parts of the mine may require a physical inspection — is the fan running? Has the drive or airway been filled with backfill or other blockages? From the lesson System Dynamics Simulation Using Stock-and-Flow Diagrams This module will introduce you to the concepts of systems dynamics modeling and will show you how to use Vensim to run a pre-existing system dynamics model. Lecture 5B: Defining Stocks Lecture 5C: Flow and Control Variables Taught By. Try the Course for Free.
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