Porosity model and air leakage flow field simulation of goaf based on DEM-CFD

  • Gang Wang
  • Hao Xu
  • Mengmeng Wu
  • Yue Wang
  • Rui Wang
  • Xiaoqiang Zhang
Original Paper


The air leakage in goaf can easily lead to disasters such as spontaneous combustion process of residual coal and gas accumulation, threatening production safety in underground coal mines. In order to study and master air leakage flow field distribution in goaf, the particle flow numerical simulation software PFC3D is used for the simulation of the collapse of overlying rock strata with the actual situation of the 3308 working face of Liangbaosi Coal Mine in China taken as an example. The quantitative porosity data of goaf are extracted and imported into FLUENT to simulate the air leakage flow field in goaf. The results show that (1) the porosity in the central part and near the working face of goaf is relatively large. With the increase of the length of goaf, the porosity decreases, and with the increase of the height of goaf, the porosity in the two cross headings is first larger than that in the central part and then smaller than that in the central part. (2) The data of air flow along the dip direction of working face obtained through the CFD numerical simulation is consistent with the actual measurement results basically, which validate the simulation. (3) The main air leakage occurs in the range of 0–10 m along the dip direction of working face. In the case of relatively large air supply rate, the residual coal spontaneous combustion area in goaf is far from the working face and the spontaneous combustion area becomes relatively large, resulting in increased risk.


Goaf Air leakage Porosity DEM CFD 


Funding information

The authors would like to acknowledge the support of the National Key Research and Development Program of China (Project No. 2017YFC0805201), National Natural Science Foundation of China (Project No. 51674158), the Taishan Scholar Talent Team Support Plan for Advantaged & Unique Discipline Areas, the Source Innovation Program (Applied Research Special-Youth Special) of Qingdao (Project No. 17-1-1-38-jch), and the Open Fund of Hebei State Key Laboratory of Mine Disaster Prevention(Project No. KJZH2017K10), as well as Shandong University of Science and Technology Research Fund (Project No. 2015JQJH105).

Supplementary material

12517_2018_3499_MOESM1_ESM.c (19 kb)
ESM 1 (C 18 kb)


  1. Byon C, Kim SJ (2013) The effect of the particle size distribution and packing structure on the permeability of sintered porous wicks. Int J Heat Mass Transf 61:499–504CrossRefGoogle Scholar
  2. Cheng WM, Yu HM, Zhou G, Nie W (2016) The diffusion and pollution mechanisms of airborne dusts in fully-mechanized excavation face at mesoscopic scale based on CFD-DEM. Process Saf Environ Prot 104:240–253CrossRefGoogle Scholar
  3. Cheng WM, Hu XM, Xie J, Zhao YY (2017) An intelligent gel designed to control the spontaneous combustion of coal: fire prevention and extinguishing properties. Fuel 210:826–835CrossRefGoogle Scholar
  4. Cheng WM, Liu Z, Yang H, Wang WY (2018) Non-linear seepage characteristics and influential factors of water injection in gassy seams. Exp Thermal Fluid Sci 91:41–53CrossRefGoogle Scholar
  5. Cundall PA, Strack ODL (1979) A discrete numerical model for granular assemblies. Geotechnique 29:47–65CrossRefGoogle Scholar
  6. Deng QW, Liu XH, Lu C, Lin QZ, Yu MG (2013) Numerical simulation of spontaneous oxidation zone distribution in goaf under gas stereo drainage. Procedia Eng 52:72–78CrossRefGoogle Scholar
  7. Ding HC, Jiang ZG, Zhu QM (2012) Optimized parameters and forecast analysis of high-position hole for goaf gas drainage. Procedia Eng 45:305–310CrossRefGoogle Scholar
  8. Ding XB, Zhang LY, Zhu HH, Zhang Q (2014) Effect of model scale and particle size distribution on PFC3D simulation results. Rock Mech Rock Eng 47(6):2139–2156CrossRefGoogle Scholar
  9. Gao FQ, Stead D, Coggan J (2014) Evaluation of coal longwall caving characteristics using an innovative UDEC trigon approach. Comput Geotech 55:448–460CrossRefGoogle Scholar
  10. Itasca Consulting Group Inc (2010) PFC2D-particle flow code in two dimensions. Ver. 4.0 user’s manual. ICG MinneapolisGoogle Scholar
  11. Kurnia JC, Sasmito AP, Mujumdar AS (2014) CFD simulation of methane dispersion and innovative methane management in underground mining faces. Appl Math Model 38(14):3467–3484CrossRefGoogle Scholar
  12. Luo HS, Quintard M, Debenest G, Laouafa F (2012) Properties of a diffuse interface model based on a porous medium theory for solid–liquid dissolution problems. Comput Geosci 16(4):913–932CrossRefGoogle Scholar
  13. MacDonald MJ, Chu CF, Guilloit PP, Ng KM (1991) A generalized Blake–Kozeny equation for multisized spherical particles. AICHE J 37(10):1583–1588CrossRefGoogle Scholar
  14. Menon KG, Patnaikuni VS (2017) CFD simulation of fuel reactor for chemical looping combustion of Indian coal. Fuel 203:90–101CrossRefGoogle Scholar
  15. Ni GH, Cheng WM, Lin BQ, Zhai C (2016) Experimental study on removing water blocking effect (WBE) from two aspects of the pore negative pressure and surfactants. J Nat Gas Sci Eng 31:596–602CrossRefGoogle Scholar
  16. Pan RK, Cheng YP, Yu MG, Lu C, Yang K (2013) New technological partition for “three zones” spontaneous coal combustion in goaf. Int J Min Sci Technol 23(4):489–493CrossRefGoogle Scholar
  17. Ren TX (2009) CFD modelling of longwall goaf gas flow to improve gas capture and prevent goaf self-heating. J Coal Geol 3:225–228Google Scholar
  18. Schatzel SJ, Karacan CÖ, Dougherty H, Goodman VR (2012) An analysis of reservoir conditions and responses in longwall panel overburden during mining and its effect on gob gas well performance. Eng Geol 127:65–74CrossRefGoogle Scholar
  19. Szlazak J (2001) The determination of a co-efficient of longwall gob permeability. Archives of Mining Sciences 46(4):451–468Google Scholar
  20. Tan B, Shen J, Zuo DF, Guo XP (2011) Numerical analysis of oxidation zone variation in goaf. Procedia Eng 26:659–664CrossRefGoogle Scholar
  21. Tang MY, Jiang BY, Zhang RQ, Yin ZQ, Dai JL (2016) Numerical analysis on the influence of gas extraction on air leakage in the gob. J Nat Gas Sci Eng 33:278–286CrossRefGoogle Scholar
  22. Taraba B, Michalec Z (2011) Effect of longwall face advance rate on spontaneous heating process in the gob area—CFD modelling. Fuel 90(8):2790–2797CrossRefGoogle Scholar
  23. Wang T, Zhou WB, Chen JH, Xiao X, Li Y, Zhao XY (2014) Simulation of hydraulic fracturing using particle flow method and application in a coal mine. Int J Coal Geol 121:1–13CrossRefGoogle Scholar
  24. Wang G, Wu MM, Wang R, Xu H, Song X (2017) Height of the mining-induced fractured zone above a coal face. Eng Geol 216:140–152CrossRefGoogle Scholar
  25. Wolf KH, Bruining H (2007) Modelling the interaction between underground coal fires and their roof rocks. Fuel 86(17–18):2761–2777CrossRefGoogle Scholar
  26. Wu JJ, Liu XC (2011) Risk assessment of underground coal fire development at regional scale. Int J Coal Geol 86(1):87–94CrossRefGoogle Scholar
  27. Yang YL, Li ZH, Tang YB, Liu Z, Ji HJ (2014) Fine coal covering for preventing spontaneous combustion of coal pile. Nat Hazards 74(2):603–622CrossRefGoogle Scholar
  28. Yu ZY, Yang SQ, Qin Y, Hu XC, Cheng JW (2015) Experimental study on the goaf flow field of the “U+I” type ventilation system for a comprehensive mechanized mining face. Int J Min Sci Technol 25(6):1003–1010CrossRefGoogle Scholar
  29. Yuan LM, Smith AC (2008) Numerical study on effects of coal properties on spontaneous heating in longwall gob areas. Fuel 87(15–16):3409–3419CrossRefGoogle Scholar
  30. Zhang Z, Ji SF (2016) Numerical simulation of particle/monolithic two-stage catalyst bed reactor with beds-interspace distributed dioxygen feeding for oxidative coupling of methane. Comput Chem Eng 90:247–259CrossRefGoogle Scholar
  31. Zhao ZL, Wen ZJ (2017) Design and application of a mining-induced stress testing system. Geotech Geol Eng 5:1–10Google Scholar
  32. Zhu HQ, Liu XK (2012) Theoretical investigation on the relationship between tail roadway methane drainage and distribution of easily spontaneous combustible region in gob. Saf Sci 50(4):618–623CrossRefGoogle Scholar

Copyright information

© Saudi Society for Geosciences 2018

Authors and Affiliations

  • Gang Wang
    • 1
    • 2
    • 3
  • Hao Xu
    • 2
  • Mengmeng Wu
    • 4
  • Yue Wang
    • 2
  • Rui Wang
    • 2
  • Xiaoqiang Zhang
    • 2
  1. 1.Mine Disaster Prevention and Control-Ministry of State Key Laboratory Breeding BaseShandong University of Science and TechnologyQingdaoPeople’s Republic of China
  2. 2.College of Mining and Safety EngineeringShandong University of Science and TechnologyQingdaoPeople’s Republic of China
  3. 3.Hebei State Key Laboratory of Mine Disaster PreventionNorth China Institute of Science and TechnologyBeijingChina
  4. 4.Department of Architecture and Civil EngineeringCity University of Hong KongHong KongChina

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