Title: Prevention methods development against aerosol terrorism for ventilation of Tbilisi subway Grant N 216968 Report - Numerical modeling of aerosol spread process in the Tbilisi Metro Ventilation System

Key personnel of the project Professor Omar Lanchava Dr Giorgi Nozadze Dr Nino Arudashvili Foreign consultants: Professor Nikolae Ilias Department of Mechanical Engineering, Industrial and Transport, University of Petrosani, Romania Professor Roland Moraru Vice-rector of University of Petrosani Department of Mining, Surveying and Civil Engineering

General Technical Data of Tbilisi Metropolitan Number of Tbilisi operating Metro stations - 23; Total length - 26.4 km; Average length of transverse tunnels - 1000 - 1200 m; Transverse tunnel cross section - 16 m2; The length of the stations - 102 m; The capacity of the stations - 50000 - 150000 m3; Depth of deployment of stations 10 - 60 m; Train composition - 3-4 Wagon; The Wagon dimention – L0 = 19.2 m , b0 = 2.7 m , h0 =3.6 m;  The maximum number of train pairs per Hour – 36.

Scenarios for the description of potential risks in the spread of hazardous aerosols for Metro Tbilisi 1. Entrance the Metropolitan till escalator tunnels - High risk; 2. Escalators tunnels- High risk; 3. Stations - High risk; 4. Wagons - High risk; 5. Ventilation hole to land surface - High risk.

The forming of tasks of numerical modeling the distribution of air flows with hazardous aerosols on the potential risk locations. Determine the flow rate of the air in the tunnel of the subway (research of the impact of the piston effect); Determination of ventilation air rate and determination of critical doses of the aerosols for worse ventilation scenarios for subway ventilation systems (stations, escalator tunnels, vestibules) in Tbilisi Metro; Determining the rate of ventilation air flow in various metro wagons and determining the appropriate critical doses of aerosols.  Determining the rate of absorbed air from the surface of the land by vertical duct hole and determining the appropriate critical dose of aerosols. Determination of ventilation air flow rate caused by heat regimes and its impact on the distribution of critical dosages of aerosols.

Numerical modeling of piston effect ( In the soft PYROSYM 2016 ) Modeling options: Length of the tunnel - L0 = 1000 -1200 m; Cross section of the tunnel - S0 = 16 m2, Train length - Ltr = 60 - 80 m; The size of the cross section of the train - Str = 4, 5, 6,25 m2 Modeling time - 600 seconds The velocity of air flow in portal cross section - 6, 8, 10, 12 m / s Lookup volum: Distribution of the flow rate in the tunnel

Results of numerical calculation Train location in the tunnel 900 m 800 m 700 m 600 m

Results of numerical calculation Train location in the tunnel 900 m from portal

Results of numerical calculation Train location in the tunnel 800 m from portal

Train location in the tunnel 700 m from portal რიცხვითი კვლევის შედეგები Train location in the tunnel 700 m from portal

Results of numerical calculation Train location in the tunnel 600 m from portal

Quasi-stationary nature of Piston effect including the turbulent zones

Results of numerical calculation Velocity detectors data from portals and near the train cross section

Determination of flow rates during the piston effect Train speed in metro tunnel Vftr m/s Air flow relative velocity in the metro tunnel during the piston effect V'fp1,2 m/s Air flow rates in the metro tunnel during the piston effect Q'1,2 m3 / s Air flow Volume in the metro tunnel during the piston effect Q'1,2 m3 1 7 16 2011 2 10 3 48 4224 12 4 64 4693 14 5 80* 5029 In the conditions of Tbilisi subway experimental calculation of Air rate by piston effect was not more 100 m3 / s in traffic at 60 km / h

Depending of air flow rate on the train speed in the metro tunnel.

Thank you for your attention