You can use it in the following web version of the model (press go button, and then click whenever you want to add ignitors). The Visible-Particles? switch will change between seeing the incandescent particles moving or seeing the flame effect on the air patches. ![]() ![]() Y-speed value controls the velocity of the particles, and the density slider will control the amount of incandescent particles that a particular ignitor will produce (in fact, it is a probability of production). You can set up a value for the wind (negative values blowing to the left, and positive ones to the right), and switching on the Varying-Wind? variable, the wind will automatically change its strength and, possibly, direction. The Boxed? option will make vertical borders to act as walls, so, once the particles are there, they only can move upwards. All we need now is to color the patches in order to show the flames (by default, the particles will be hidden), and add some extra functionalities to create ignitors with the mouse (places where the incandescent particles born) or wind effect (some horizontal movement to the particles). That's all the important to get very realistic flame effects. Patches-to-move is a report that returns only the patches above the particle. Report (patch-set patch-at 0 1 patch-at -1 1 patch-at 1 1) Patch Report: Returns the patches above it It modifies the Temperature of the air patch if location is out of the world, the particle is removed ![]() It moves up, to one of the cells with higher difference in temperature Set Temp-Part Temp-Part - ifelse-value (Temp-Part > Temp-air) The cooling depends on the temp of the cell it occupies Every Particle gets cooler, ascend and heat the air cell Reduce Air Temperature by natural cooling. Only particles with positive temperature will survive, it is not worth to keep alive particles that will not produce new fire.Īll these ideas are implemented in the next procedure: to go.Simultaneously, every air cell diffuse its temperature to neighbours cells (according to a Heat Conductivity parameter) and all of them get a little bit cooler.Once there, the air cell increments its temperature because of the presence of an incandescent particle in it.In this way we get something like flows of ascending particles. In every step, each particle moves, preferably upwards, towards the neighbour air cell with more similar temperature to it.Temp-air Temperature of every patch (air cell)Īs in the other cases, we are not interested in replicate the physical processes ocurring during the fire production, but in creating some conditions where we can recognize its effects. For the particles we will make use of turtles, while the air will be modeled with patches.Īll the elements (incandescent particles and air) have a property to store their individual temperature ( Temp-part and Temp-air, respectivelly) as the followin code suggests. In the models presented here we will separate the incandescent particles from the air (with oxygen) around them. Because the most common and graphical picture of fire is the flame, we will be interested in this post in simulate flame productions. The flames are the parts of the fire that emit visible light, while smoke are physically the same but that no longer emit. This is known as the fire triangle.įire is formed by a set of incandescent particles or molecules of combustible material capable of emitting visible light. If any of them finishes, the combustion will stop. ![]() The reaction will keep going as long as there is enough heat, fuel and oxygen. The fuel must be heated to its ignition temperature for combustion to occur, and this temperature depends on the type of fuel. Combustion that results in a flame is very fast and is called burning. It can be slow or fast depending on the amount of oxygen available. It occurs between oxygen in the air and some sort of fuel, and the products from the chemical reaction are completely different from the starting material.Ĭombustion is when fuel reacts with oxygen to release heat energy. Following with the simulation of Classical Elements in NetLogo, and after Earth and Water, we will address in this post how to simulate some fire features, but taking into account the same goals of decentralized and as simple as possible models.Īccording to Science Learning Website, fire is the visible effect of the process of combustion, a special type of chemical reaction.
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