fluent 教程 粉煤燃燒

1、粉煤燃燒 模擬連續(xù)相與稀疏相煤顆粒燃燒 煤顆粒穿越氣體，經(jīng)過揮發(fā)份揮發(fā)，碳核燃燒，產(chǎn)生氣相燃燒的源項 采用有限速率化學(xué)動力學(xué)或混合分?jǐn)?shù)PDF模擬 下面介紹混合分?jǐn)?shù)PDF模擬 1，用prePDF建表 2，給定PDF化學(xué)模擬 3，指定煤顆粒為稀疏第二相 4，求解包括系數(shù)顆粒反應(yīng)在內(nèi)的氣固兩相流問題長10米，直徑為1米的管道型燃燒室，二維，算一半0.5米中心0.125米以內(nèi)，速度50米/秒其它0.375米為15米/秒，溫度1500K煤粉在告訴氣流中加入，質(zhì)量流量為：0.1kg/s (總共為0.2kg/s)腔體壁面溫度1200K，雷諾數(shù)：100000，為湍流混合分?jǐn)?shù)PDF模型一，用PDF系統(tǒng)研究絕熱系

2、統(tǒng)Set-case擊活二次流（揮發(fā)份）（燃料流為碳核）Empirically defined Streams絕熱化學(xué)平衡組分的選擇：Setup-species13組分13 species: C, C(s), CH4, CO, CO2, H, H2, H2O, N, N2, O, O2, and OH. 給定煤燃料組分Setup-species-composition燃料：C5H12質(zhì)量分?jǐn)?shù)1氧化劑：O2，摩爾分?jǐn)?shù)0.21N2， 摩爾分?jǐn)?shù)0.79ElementMassWt %MolesMole FractionC(89.3 - 69.6)0.655.40.24H5.00.16160.70O3.4

3、0.110.70.03N2.30.080.60.03Total30.422.7密度Setup-species-densityH2O(L):1000C(s): 1700進口條件Setup-operating conditions燃料進口：303K氧化劑進口650K 定義PDF求解條件Setup-solution parameters保存輸入?yún)?shù)：file-write-input求解：calculate-PDF table保存PDF文件：file-write-PDF檢查PDF計算結(jié)果Graphics-Property Curves溫度混合分?jǐn)?shù)之間關(guān)系：f=0.1；T2270K組分在混合分?jǐn)?shù)空間分布

4、非絕熱的設(shè)置和PDF計算Operating conditionSetup-solution ParametersFLUENT 計算讀入網(wǎng)格檢查網(wǎng)格顯示網(wǎng)格非耦合求解器標(biāo)準(zhǔn)雙方程模型PDF模型（非預(yù)混模型）離散相與氣相耦合：define-models-discrete phaseDefine-InjectionsGroup injectionNumber of particles streams: 10Particle type: dropletMaterial: n-pentane-liquidDiameter distribution: linearEvaporating species:

5、C5H12Stochastic model: number of tries: 10First PointLast PointX-Position (m)0.0010.001Y-Position (m)0.0010.001X-Velocity (m/s)100100Y-Velocity (m/s)057.7Diameter (m)1.0E-41.0E-4Temperature (K)303303Flow Rate (kg/s)2.0E-42.0E-4These initial conditions define the spray of liquid fuel droplets with a

6、uniform diameter of 100 microns. The filled spray cone of 30 degree half-angle is defined by the range of Y-Velocity from 0 to 57.7 m/s. The total mass flow rate is 10 2.0E-4 = 0.002 kg/s. This corresponds to the mass flow of liquid fuel in the half of the symmetric duct considered here. Material: (

7、continuous phase)Cp: mixing-lawThermal conductivity: 0.025Viscosity :2.0e-5Materials: Discrete PhaseMaterials type: droplet-particleN-pentane-liquidDensity620 kg/m3Cp2300 J/kg-KThermal Conductivity0.136 W/m-KLatent Heat3.63E5 J/kgVaporization Temperature303 KBoiling Point306 KVolatile Component Frac

8、tion (%)100Binary Diffusivity6.1E-6 m2/sSaturation Vapor Pressure8.2E4 PaHeat of Pyrolysis0 J/kg邊界條件：Set solutionP1: 松弛因子設(shè)為1初始化流場檢查求解結(jié)果，顯示，輸出顯示顆粒軌道：display-Particle Tracks顯示組分分布：display-contours 包括氧氣，二氧化碳，水，一氧化碳等計算通過計算區(qū)域邊界的通量：Report-Fluxes: mass flow rate, total heat transfer rate, Radiation heat transfer rate et al.計算氣相和離散相之間的換熱Report-Volume Integrals小節(jié) 煤燃燒的模擬過程包括揮發(fā)份揮發(fā)和碳核的燃燒，以及氣相的燃燒過程。本小節(jié)是用PDF混合分?jǐn)?shù)化學(xué)平衡模型模擬氣相燃燒。燃料的分解組分由prePDF給定，燃料的燃燒根據(jù)平衡系統(tǒng)