Particle time step size fluent. fluent中time step size-3.

Particle time step size fluent youtube. Smallest grid size is 0. 16 answers. The default is False. 1、在进行unsteady 计算的时候，fluent是从前一个时间算到下一个时间（即time steps），而每个时间步长内的计算就相当于一个准稳态求解，因此需要设置Max Iterations per Time Step；在这个时间步长内的计算就是一个稳态过程，在达到iteration次数之前收敛完成，就跳到下一个time step，否则就将所规定的迭代 When solving unsteady equations for the continuous phase, you must decide whether you want to use Fluid Flow Time Step to inject the particles, or whether you prefer a Particle Time Step Size independent of the Fluid Flow Time Step. Given a slight disturbance those can move towards gas outlet or collection bins. contains a selectable list of the cell zones in which you can use the MPM. 001s, number of time step 2000 是什么意思？它们有和关系？应该怎么设置呢？步长0. 模型描述本案例模拟甲醇在鼓风雾化器中的雾化，甲醇在被引入鼓风雾化器之前被冷却到-10℃。雾化器中… Jun 7, 2023 · So defining a large particle time step size leads to inappropriate results and provokes time step independence study. the reciprocal of the particle time step but how should I determine the particle time step as I Hi, I am using fluent discrete phase model for particle-laden jet flow modelling. fluent中dpm模型的udf（二）：曳力. It differs from the Length Scale in that it allows ANSYS FLUENT to compute the time step in terms of the number of time steps required for a particle to traverse a computational cell. 01sec time step size. New videos will be posted herehttps://www. I already read some earlier threads regarding this, but couldn't Step Length Factor also controls the time step size used to integrate the equations of motion for the particle. is a number of sub-time steps for particle tracking in each flow time step. 01 and 1000 time steps in the DPM model dialogue box. 图中颗粒为非稳态即瞬态追踪，其中Particle Time Step Size与Number of Time Steps需要用户给定，而后者的含义困扰了我很久，今天通过改变这个参数观察了计算结果。 Fluid Flow Time Step enables injection of particles for every fluid flow time step. 2 sec but the time step for particle set to 0. 001m and particle diameter is 1/4 of this grid size. Ansys Fluent sets the inlet’s and outlet’s DPM boundary conditions to Ansys Fluent; Ansys Meshing; Analysis; Design Modeler; Post-Processing; Particle time step size. 001 Particle Type : Droplet, Injection type : cone , Particle temperature: 307k , velocity: 5m/s Volatile part : 98% Inlet continuous phase : Velocity : 0. 12. nAccording to the calculation of collision time and martial properties mentioned above, I should use time step size about 10^-5, with 100000-time steps, which supposed to have longer iteration time. , 1. 勾选Unsteady Particle Tracking，则表示非稳态追踪，否则为稳态跟踪。 则将按一定的时间步长对每个粒子进行追踪，而不一定到达指定边界，计算达到时间步长之后，则更新连续相。应当指出，Unsteady Particle Tracking和连续相的稳态非稳态无关。 但是瞬态计算中如果设置particle time step size为0. If this estimated transit time is defined as , FLUENT chooses a time step as (22. 051s 注入第二个 224 个粒子, 0. 001s. The R TD curve at Point 2 has a very narr ow peak. 001, the particle collision with the wall is shown schematically incorrect. With the latter option, you can use the Discrete Phase Model in combination with changes in the time step for the continuous equations, as it is done when using Jul 26, 2024 · 对Fluent中 的DPM模型基本 而积分步数约等于颗粒时间步长（Particle Time Step Size）除以积分时间步长，但以 Max Number of Feb 26, 2022 · with the given particle time step 0. In any case, the particles will always be tracked in such a way that they coincide with the flow time of the continuous flow solver. Please see attachment for details on calculating the parcel size Key word: DEM, DDPM, parcel size, time step size, parcel mass Track With Fluid Flow Time Step: By activating this option, the time step size of the discrete phase equals the time step size of the continuous phase, the other choice is to define Particle Time Step Size In addition, you can set particles injection time at “Inject Particles at”; it should be coordinated with the Particle time step or Fluid flow time step. (f) Enter 0. 5 s=1742- time step size for injection and （2）Particle Treatment. Oct 13, 2024 · 点击“CFD之仿真区”关注公 众号交流学习→概述在非稳态（非定常）问题中，涉及到时间变量的设置会比较纠结，主要是求解器中的时间步长（Time Step Size）、时间步数（Number of Time Steps）和单位时间最大迭代次数（Max Iterations per Time Step）三个参数如何设定？ 知乎，中文互联网高质量的问答社区和创作者聚集的原创内容平台，于 2011 年 1 月正式上线，以「让人们更好的分享知识、经验和见解，找到自己的解答」为品牌使命。知乎凭借认真、专业、友善的社区氛围、独特的产品机制以及结构化和易获得的优质内容，聚集了中文互联网科技、商业、影视 在离散相非稳态计算中，粒子是以particle timestep size的时间步长来喷射颗粒的，颗粒喷射完之后就要跟踪其轨迹，这时又要用到积分时间步长的概念，由于两次喷射之间的时间间隔是particle timestep size，这就要求积分时间步长一定要小于或者等于particle time step size，否则颗粒就会“走过头”。 《探讨Fluent中的时间步长》 在计算流体动力学（CFD）领域，时间步长（time step size）是一个至关Hale Waihona Puke Baidu要的参数。它直接影响着仿真的精度、稳定性和计算效率。在这篇文章中，我们将深入探讨Fluent中时间步长的设定和调整，以及其对仿真结果的影响。 1. May 20, 2016 · 3-The time step based on your mesh accuracy for good results the smallerest meam good results but it depends on your grid size. 001s更新一次颗粒位置，这个更新颗粒位置的过程就是对颗粒运动方程进行一次积分，而我理解积分时间应该等于0. 001s 开始注入第一个 224 个粒子, 0. nThe DPM_Heat_Mass UDF is called several times per particle iteration, as far as I understood for every point of the particle trajectory. Whether to provide the particle time. In the DPM box there is the option to track the discrete phase with the fluid flow timestep or, if the box is unchecked, to enter a time step size manually. 003. 0025 it should take 500 iterations for full particle release (1008 particles), so shouldn't I see particle tracked at this point to = 1008? any advice would be much appreciated!! Apr 26, 2022 · 文章浏览阅读2. I have read in other forums that this can be solved by changing the input mass flowrate in the DPM model, however I have not tried this yet. The default is 500. Jul 10, 2020 · Please subscribe to our new Channel. If the particle time step computed by Ansys Fluent (and passed as an argument) is smaller than this value, then Ansys Fluent’s time step is returned. In case, I choose "Unsteady Particle Tracking" , these parameters refer to what step ? What time ? Start time, Stop Time The Particle Time Step size Number of time Steps Max. When I run the simulation, Fluent recognizes the number of parcels but the status for the parcels it prints on the console is wierd. This forces me to work with instationary particles (although I am looking for a steady solution, where the particle collisions dictate the spread). Particle Time Step Size：输入0. 5 s=1742- time step size for injection and fluid =0. 006912 m^2 particle treatment : unsteady particle tracking & track with the fluid flow time step according to my calculation, the particle number should be around 15000~18000, but after the simulation, the no. 001s Nov 5, 2019 · In ANSYS Fluent, the trajectory of a solid discrete particle is evaluated by integrating the force balance on the particle that equates the inertia of the particle with the forces acting on it and this can be described by the following relation (6) d u → p dt = u →-u → p τ r + g → (ρ p-ρ) ρ p + F → where u and u p are the fluid and particle velocity, ρ and ρ p are the fluid and Dec 1, 2009 · DPM particle time step #1: amos. I appreciate any advice on setup and/ or parameter that can help in Whenever the particle tracker is run, the DPM sources are updated. Therefore, I am using the DEM collision model available in Fluent. Max. The 后处理中显示 Particle Residence Time （粒子停留时间），同时控制面板显示 number tracked = 146, escaped = 146 。 以文章 16 中的案例为例，我们使用的就是稳态追踪， Wall 边界设置为 Reflect 、 Outlet 边界设置为 Escape ，表示粒子遇到 Wall 会反弹，只有遇到 Outlet 才会从流场中流出。 但是瞬态计算中如果设置particle time step size为0. 36. Best assumption for incomplete is to keep them with the particles of similar size. The particle separation vector r n is defined by: r n = X 1n - X 2n Where X 1n and X 2n are the coordinates of the particle-1 and particle-2 at the end of nth time step in the laboratory frame. My idea is to inject particles, until the You can use a user-defined function (DEFINE_DPM_TIMESTEP) to change the time step size for DPM particle tracking. 05s 注射一次,比如 start time=0. 5. But then I only inject every 1 of 100 particle iterations (it only lasts one particle iteration each new time step). fluent中dpm模型的udf（一）：边界条件. As the particle is moved along its trajectory, heat and mass transfer between the particle and the continuous phase are also computed via the heat/mass transfer laws (Laws for Heat and Mass Exchange in the Theory Guide). . Jun 21, 2013 · Could someone please tell me how to determine time step size number of time steps and max iterations per time step: guido_88: FLUENT: 4: August 30 fluent中time step size-3. 0005 and 0. 0001 for Particle Time Step Size. But if the same injection done with a 1 micron particle , all the particles that are tracked are escaping. com/channel/UC34GHDwqDux32A2GZ_MDIMAIn this video, it is shown how to Feb 27, 2012 · fluent里 time step size 0. MR CFD » Blog » Particle time step size. Step length Factor: 5. The particle should be, 1)small enough, e. Notice that, in the one-way method, the effect of particle motion on the continuous phase is ignored, so the source term keeps 0. In DEM simulations parcel size is used for the collision calculations. step_size: float, optional. Multiphase-Specific Time Stepping. Enable It is used to compute time step size. For steady particle tracking, there is an option of specifying step length factor/length scale to specify the time step that will be used for Lagrangian particle equation solutions. 2s，run calculation里time of interations 设置为200，最后particle track时只得到了4s时的颗粒的位置和速度信息，想问怎么设置才能得到help里如下图所示这样的过去各时间段的颗粒位置等信息？ Particle Zones. Whenever the particle tracker is run, the DPM sources are updated. 001，则粒子在本时间步内释放了五次，可以总结：Track with Fluid Flow Time Step，则颗粒在一个时间步内只在计算连续相前释放一次；Inject Particles at，Particle Time Step，则释放次数=时间步长/Particle Time Step Size。 Dec 14, 2020 · Nevertheless, I am interested in how fluent calculates the time step size of every iteration within this particle time step. I need that to solve the differential equations of my particle model for the species distribution. Breakup The breakup model should be activated in simulations where the droplets breakup is highly probable or is a part of instructions like in sprays. 000508 kg/s size of inlet surface : 0. 001s, 每次注射 224 个粒子的话,那么 0. in fluent injection panel you can choose between injecting particle at fluid time step or at particle time step. If False, element values are provided. Oct 4, 2002 · How about to use 'Particle Track', which I use very frequently to check residence time. See Options for Interaction with the Continuous Phase for more information. 91 s less on a mass-weighted average (which is 89. The defined fixed time step size of 1e-5 might still be too large (I don't know how fast your process is). For each time step, the particles next position is calculated based on the previous conditions of velocity, position etc. 000 elements 26. Amine. 01 1. For example, if I get 10 particles present at time t in front of the face, then I can define some probability like X out of 10 particles will be inhaled by the person at time Jan 9, 2020 · increasing the maximum number of time steps used to compute a single particle trajectory. Inputs for Time-Dependent Problems. You may be able to reduce this discrepancy by changing the tracking parameters, that is, increasing the maximum number of time steps used to compute a single particle trajectory . mass flow rate = 5*10^-19- number of released particles in 2. by 500. 101s 注入第三个 224 个粒子,是隔着时间步不断注入粒子的过程,每次注射后的粒子都在计算,都在向前 You can use a user-defined function (DEFINE_DPM_TIMESTEP) to change the time step size for DPM particle tracking. Whatever I understood that if I set length scale or step length factor, then fluent will calculate integration time step size. As mentioned in Section 26. Hi Amir sir In my heat sink cooling problem actually I want relative humidity of 15% at the exit of the sink but I am getting it 7. nUsing an UDF I managed to switch injections on and off by changing the injection time (start/stop) each fluid time step. Particle Time Step Size specifies particle time step size for the calculation. node_value bool, optional. 001秒，步数2000，也就是模拟的时间长度为 2 秒 Currently I had an issue about the time step size. To solve a transient problem, you will follow the procedure outlined below: See full list on mr-cfd. The present CFD project simulates the injection of solid particles as fuel inside the combustion chamber via ANSYS Fluent software. For steady-state simulations, you also must specify an appropriate Particle Time Step Size and the Number of Time Steps, which will control the spray density. Apr 16, 2024 · Hello everyone, I ran a transient and unsteady particle tracking simulation and I got the number of escaped and trapped particles via particle track ->particle ID, and the report type is summary. The default is True. I am simulating particle capture in multi-layer screens in fluent using DPM. The particle time step is limited to a fifth of the particle relaxation time. particle at previous time step F p,t C tangential contact force on the particle F p,t C,t tangential contact force on the particle at current time step F p,t C,t-dt tangential contact force on the particle at previous time step F p fp fluid-particle interaction forces on the particle F f pf fluid-particle interaction forces on the fluid F p (e) Retain the Unsteady Particle Tracking option in the Particle Treatment group box. In that i define my injection as surface injection with a particle size of 50 microns . From the results of this simulation, we realized that the effect of the time step size parameter on the behavior of particles is very effective. Pathlines steps. Mar 18, 2022 · The required time step size is proportional to the mesh size, so what you see is normal. Pathlines step size. My question is, how does time step size affect fluid flow? 三十三、Fluent边界条件湍流参数设置详解 勾选Unsteady Particle Tracking. Government Classified, Controlled Unclassified Information, International Traffic in Arms Regulators (ITAR) or Export Administration provide_particle_time_field: bool, optional. I have consulted the user manual to no avail. New Member . However, the time step can be changed if you have decreased the max number of steps as a controlling criterion. g. Oct 28, 2019 · continuous phase time step size : 3*10^-5 s mass flow rate : 0. As Regards the number of particle streams, more elevated is its number more accourated the analysis of the atomization; usually, I adopted 200/300 particle streams. com/channel/UC34GHDwqDux32A2GZ_MDIMAIn this video, it is shown how to Jul 23, 2007 · The integration time step is computed by FLUENT based on a characteristic time that is related to an estimate of the time required for the particle to traverse the current continuous phase control volume. You are prohibited from providing (i) information that is confidential to You, your employer, or any third party, (ii) Personal Data or individually identifiable health information, (iii) any information that is U. Can i know why is this discrepancy. e-09 meter, and 2) density is similar or very low compared to the gas phase density, Mar 14, 2022 · Topics related to Fluent, CFX, Turbogrid and more. Particle Sub-Timesteps within each Flow Timestep. 0002 for Particle Time Step Size (s). Feb 24, 2016 · If you have to run a simulation for 200 seconds then you have to take the number of time steps 2000 for 0. Postprocessing for Time-Dependent Problems. 5m/s, mass fraction equal to the 50% RH, temperature : 293k Whenever the particle tracker is run, the DPM sources are updated. 0e-5 with 100 time steps Apr 23, 2020 · I think it may have to do with particle drag, and must switch to unsteady tracking and give separate particle time step April 24, 2020, 12:04 Mesh Size Solution of the discrete phase implies integration in time of the force balance on the particle (Equation 12–1 in the Theory Guide) to yield the particle trajectory. Runtime Discrete Fourier Transformation. Covers various combustion applications from liquid fuel sprays to biomass combustion and fluidized bed systems. 11-2) where is the Step Length Factor. Number of Time Steps allows you to specify the Apr 22, 2014 · Secondly, the time step size of my continuous phase is 1e-5 and I keep my particle time step size as 0. May 5, 2012 · When you're setting the particle time step, the step size is specified and the number of steps would be set by considering the current flow field time. After the particle DPM iteration i see in the summary report that all my particles are aborted. It differs from the Length Scale because it allows FLUENT to compute the time step in terms of the number of time steps required for a particle to traverse a computational cell. I have selected a time step size of 0. You can use a user-defined function (DEFINE_DPM_TIMESTEP) to change the time step size for DPM particle tracking. Apr 24, 2019 · 各位老师好，单个颗粒追踪，我在DPM模型中点击unsteady particle tracking 后，particle time step size设置为0. For more information about changing the time step size for DPM particle tracking, see DEFINE_DPM_TIMESTEP in the Fluent Sep 17, 2015 · If the fluid is moving faster than the particle, it accelerates, if slower, it decelerates, and this applies all 3 directions, so the fluid also causes the particle to change direction. Sep 8, 2014 · dear Cees i want to inject particles into the domain for example every 0. How can I set position and numbers of particle in DPM fluent as initial value Advanced DPM combustion package featuring 8 comprehensive ANSYS Fluent exercises, focusing on particle and droplet combustion phenomena. Mar 12, 2021 · (Since I am injecting 100 times per time step only every 100 particle the injection staggering is working). steps: int, optional. 01s 时间步数为10 则计算… May 18, 2023 · DPM particle tracking "flow time step size" and " particle time step size" monali2015m: FLUENT: 0: February 26, 2022 17:37: Transient simulation not converging: skabilan: OpenFOAM Running, Solving & CFD: 14: December 17, 2019 00:12: Setting up Lid driven Cavity Benchmark with 1M cells for multiple cores: puneet336: OpenFOAM Running, Solving Jan 30, 2023 · Hello, I hope you are doing well. FLUENT’s discrete particle method (DPM) is used to conduct. I am giving flow and particle time step 1. Number of Time Steps：输入10. The But still I do not find particle injection. Particle time-step and max number of steps are used only for each iteration when particles are tracked. Then what is "particle time step size" and "number of time steps". 01 s takes about 50 s and 10 s for a complete flow. While for time steps of 0. 1. 3w次，点赞51次，收藏193次。本文详细介绍了FLUENT软件中Discrete Phase Model (DPM) 的参数设置，包括Interaction（双向耦合）、ParticleTreatment（颗粒追踪方式）、Tracking（追踪设置）、PhysicalModels（物理模型）以及UDF和Numerics的相关选项。 While at the time step size between 0. Asked 23rd Feb, 2016; (optional) If you are using the explicit transient formulation or if you are using the adaptive time stepping method (described in a later step and in Section 26. When I set time step size of 1 s it takes about more than 100 s for a complete fluid flow. March 18, 2022 at 9:44 am [FLUENT] Time step too small’ is Feb 4, 2021 · The solution was successfully converged, but the calculation time took extremely long time (more than 24 hrs. 00% of the last time step). The time step size can be prescribed for special applications where a certain time step size is needed. (h) Click OK to close the Discrete Phase Model dialog box. particles tracked showed around 2 Inject Particles at,Particle Time Step 则释放次数=时间步长/Particle Time Step Size 对于颗粒包概念我不太明白，能否理解为定义的injections，比如我定义的file型有400个粒子，那么一个颗粒包就是有400个粒子？ 2n are the velocities in the laboratory reference frame of particle-1 and particle-2 in the nth time step. 005，Particle Time Step Size 设为 0. Addresses critical aspects including time-step sensitivity, evaporation modeling, and combustion chemistry. So defining a large particle time step size leads to inappropriate results and provokes time step independence study. 42% , I tried with different combinitions of particle time step size and number of time steps. As the solution progresses, Ansys Fluent reports the dynamic mesh time step and the simulation time in the console and the Time Step and Elapsed Simulation Time fields. For more information about changing the time step size for DPM particle tracking, see DEFINE_DPM_TIMESTEP in the Fluent Oct 8, 2014 · What is exact meaning of stop time in the set injection properties in the fluent under define injection ? I'm simulating sediment transport (in river) for a STEADY FLOW. Enable Interaction with Continuous Phase (if selected) enables two-way coupling between particles and fluid flow. Number of Steps: 500. 5 s Jan 17, 2013 · First of all, you have to adopt an unsteady analisys to study a spray phenomena; keep attention about the time step size. Fluent 中提供了一个调整的判断依据，在每个时间(time step) 计算的 Iterations 在 5-10 次是最理想的，因此，如果每个 time step里 Iterations 的次数大于 10，那就要把 time step size 设置更小些，如果是小于 5 的，就调大些。 Jun 11, 2021 · Hello everyone,I am simulating discrete particles and I am interested in the particle-particle collisions. 当udf程序编写并且编译成功后，在dpm模型的设置选项中，选择udf，选中dpm time step即可。 有任何问题，欢迎评论区交流。 持续更新. 001s，否则颗粒在这次积分计算中要么走过头（积分时间>0. 13. I have a question about the particle time step and the number of times the particle equation of motion is solved in a single cell for a single parcel passing through that cell. V. K-Omega SST model is used Is there a way to calculate the maximum stop time? Is this dependent on max. 2 Adaptive Time Stepping. 14% of their total age or 100. 001s，而step length factor设为5，则每隔0. Integrates multiple physics including Jan 24, 2018 · I am having some difficulties understanding how fluent determines the time step size for the DPM with unsteady particle tracking. I appreciate any advice on setup and/ or parameter that can help in Jun 30, 2021 · DPM: Interaction with continuous phase, Unsteady particle tracking, Inject particle time step :0. 1, it is possible to have the size of the time step change as the calculation proceeds, rather than specifying a fixed size for the entire calculation. Disable Track with Fluid Flow Time Step and enter 0. Number of time steps: 1. 1 s and 0. 001s Feb 4, 2021 · The solution was successfully converged, but the calculation time took extremely long time (more than 24 hrs. This process is repeated until the specified Total Time Of Erosion is reached. Whether to provide the nodal values. The purpose of this simula May 16, 2022 · If I can define the sphere/cube in front of the face, what will be the UDF to collect the number of particles (parcels) present on that sphere/cube at a certain time step. 003 and choose inject particle at fluid time step then in calculation menu Jan 15, 2025 · The Ansys Learning Forum is a public forum. My problem is the particle ID summary can only get the recent time step particle information, if I want to get the number […] Jul 21, 2022 · density = 1000kg/m3 - diameter=10^-7m - mass flow rate = 5*10^-19- number of released particles in 2. i set the time step for partile 0. 0001. 2) it is recommended that you enable the printing of the current time (for the explicit transient formulation) or the current time step size (for the adaptive time stepping method) at each iteration, using the Statistic Monitors Step Length Factor also controls the time step size used to integrate the equations of motion for the particle, as an alternative to the Length scale. for 40% Iteration). Discrete Phase Model Mar 7, 2006 · hai, Iam working on DPM problem. If the particle time step computed by ANSYS FLUENT (and passed as an argument) is smaller than this value, then ANSYS FLUENT's time step is returned. 举例：选择Inject Particle at Time Step，时间步长设为0. S. Total amount of tracking time is based on flow-time. Mar 15, 2016 · I am not able to understand the physical significance of 'particle time step size'. However in both cases we have to ensure that the volume of the parcel is smaller than the cell volume to ensure an accurate and stable solution. 1sec time step size or number of time steps20000 for 0. Apr 18, 2022 · 1、在进行unsteady 计算的时候，fluent是从前一个时间算到下一个时间（即time steps），而每个时间步长内的计算就相当于一个准稳态求解，因此需要设置Max Iterations per Time Step；在这个时间步长内的计算就是一个稳态过程，在达到iteration次数之前收敛完成，就跳到下一个time step，否则就将所规定的迭代 The DEM collision model extends the DPM model in Fluent to model dense particulate flows. Apr 25, 2021 · time step size 是物理时间步长 number of time steps 是时间步数 max iterations per time step 是一个时间步迭代的次数限制 时间步长 * 时间步数 = 计算的物理时间长度例如时间步长为0. 物理现象：对于具体的物理现象，一些特定的时间尺度可能会指导时间步长的选择。例如，对于瞬态流动问题，可以根据关注的时间尺度选择相应的时间步长大小。在Fluent中，可以通过在求解器控制台中设置时间步长参数来调整时间步长的大小。 Jan 15, 2017 · Particle Time step size 代表粒子从 start time(见下面参数 C) 开始注入流场,每隔 0. 6. com 当迭代步数不同时，则存在颗粒入射的问题，FLUENT提供了两种方式∶（1）Particle Time Step∶在每一个颗粒时间步入射颗粒。（2）Fluid Flow Time Step∶在每一个流动时间步入射颗粒。 Jan 9, 2020 · 8. Is there a way to write the time step size, time a may: FLUENT: 6: November 22, 2009 12:52: VOF I have enabled unsteady particle tracking and injecting particles at a particle time step of 0. (g) Retain the default value of 1 for Number of Time Steps. Then the continuous phase source terms need to be updated. 概念液体喷雾蒸发现象是生活中常见到的一种现象，广泛应用于化工行业，对Fluent进行设置可模拟这类现象。 2. number of Steps or Particle time Step Size? I set: Particle time steps size: 1E-06. Nov 7, 2016 · How can I set position and numbers of particle in DPM fluent as initial value? Question. What is time step size in fluent ? Question. fluent中dpm模型的udf（三）：自定义壁面温度 Jan 1, 2010 · depends on solution parameters like time step size and total sim-ulation time. cxjhs venfln ato qhomo oyidqp srplnq deqkc iweayy uvj byc ojz ngv ytppf enjtdo xidqn