1. Study of explosion propagation in elongated closed vessels Study of explosion propagation in elongated closed vessels Duration: 01.05.2013 – 31.10.2015 Director of Project: Dr. Codina Movileanu Mentor of Project: Dr. Domnina Razus Postdoctoral Research Project PN-II-RU-PD-2012-3-0035 Contract No. 17/26.04.2013

2. Financing:State budget Name of the Programme PN II: Human Resources Subprogram: Postdoctoral research project Budget300000 lei Duration of contract:30 months Contracting Authority: Executive Unit for Financing Higher Education, Research, Development and Innovation Contractor:“Ilie Murgulescu” Institute of Physical Chemistry

3. Project Budget: Budget chapter (expenses) 2013 (lei) (lei) 2014 (lei) 2015 (lei) (lei)Total(lei) Salaries 631005438627514145000 Inventory 1154310392537427309 Mobility 23454.2423900047354.24 Overhead 28775.76255252603680336.76 Total 12687311420358924300000

4. Project Summary: The main objective of this project is the experimental investigation of closed-vessel explosive combustion of fuel-air mixtures, in deflagration regime, in elongated cylindrical vessels (length/diameter > 3) in order to reveal the heat losses during flame propagation and to evaluate their impact on the flammability parameters. In these vessels, both central and side ignitions will be performed. The study will be realized with ethylene-air mixtures at various initial concentrations and various initial pressures, at ambient initial temperature. The objectives of the project are: (1) The experimental determination of the maximum explosion pressures and explosion times for ethylene-air mixtures at various p 0 in elongated cylindrical vessels with various L/D ratios; (2)The calculation of adiabatic explosion pressures for fuel-air mixtures within the flammability range at ambient p 0, using available computer packages; (3) The calculation of the maximum rates of pressure rise for fuel-air mixtures with various equivalence ratios at various p 0 in elongated cylindrical vessels; (4) The experimental determination of the propagation velocity for deflagrations of ethylene-air mixtures at various initial pressures in elongated cylindrical vessels. The knowledge of characteristic parameters of these processes allows the assessment of explosion risks for flammable mixtures in various conditions and the design of equipment and industrial plants where flammable mixtures might be formed. The study will be realized with ethylene-air mixtures at various initial concentrations and various initial pressures, at ambient initial temperature. The objectives of the project are: (1) The experimental determination of the maximum explosion pressures and explosion times for ethylene-air mixtures at various p 0 in elongated cylindrical vessels with various L/D ratios; (2)The calculation of adiabatic explosion pressures for fuel-air mixtures within the flammability range at ambient p 0, using available computer packages; (3) The calculation of the maximum rates of pressure rise for fuel-air mixtures with various equivalence ratios at various p 0 in elongated cylindrical vessels; (4) The experimental determination of the propagation velocity for deflagrations of ethylene-air mixtures at various initial pressures in elongated cylindrical vessels. The knowledge of characteristic parameters of these processes allows the assessment of explosion risks for flammable mixtures in various conditions and the design of equipment and industrial plants where flammable mixtures might be formed.

5. Project Objectives: I. Project objectives 2013 1. Experimental measurement of flammability parameters for stoichiometric ethylene-air mixtures in three asymmetrical closed vessels with central ignition at ambient p 0 and T 0 2. Examination of maximum explosion pressures and of times to reach the maximum pressure as a function of asymmetry ratio R=L/D 3. Calculation of the maximum rates of pressure rise and propagation velocities from pressure-time history and examination of their variation as a function of the asymmetry ratio 4. Experimental measurement of flammability parameters for stoichiometric ethylene-air mixtures in 3 asymmetrical closed vessels with central ignition at ambient T 0 and various initial pressures 4. Experimental measurement of flammability parameters for stoichiometric ethylene-air mixtures in 3 asymmetrical closed vessels with central ignition at ambient T 0 and various initial pressures 5. Computation of adiabatic flammability parameters 5. Computation of adiabatic flammability parameters

6. Estimated results for 2013: Flammability parameters for stoichiometric ethylene-air mixtures in three asymmetrical closed vessels with central ignition at ambient p 0 and T 0 ; Flammability parameters for for stoichiometric ethylene-air mixtures in 3 asymmetrical closed vessels with central ignition at ambient T 0 and various initial pressures.

7. Figura 3 – Viteze maxime de crestere a presiunii pentru explozia unui amestec stoichiometric etena-aer in doua celule cilindrice cu aprindere centrala (C3 avand L/D = 8.1; C2 avand L/D = 2.5) Figura 1 – Variatia de presiune (Δp) si semnalul sondei de ionizare (SI) inregistrate la explozia unui amestec stagnant 6.54 vol. % C 2 H 4 -aer in celula cilindrica avand raportul L/D = 1.5, la p 0 = 1 bar. Figura 2- Curbe presiune-timp pentru explozia initiata central a unui amestec stoichiometric etena-aer, la p 0 =, T 0 = 298 K in doua celule de explozie: 1- celula cilindrica C1 (L/D = 1.5); 2 - celula cilindrica C2 (L/D =2.5 ) Experimental results:

8. Project Objectives: II. Project objectives 2014 1.Experimental measurement of flammability parameters for ethylene-air mixtures with various initial concentrations in 3 asymmetrical closed vessels with central ignition, at ambient p 0 and T 0 ; 2.Experimental measurement of flammability parameters for ethylene-air mixtures with variable initial concentration in 3 asymmetrical closed vessels with central ignition at ambient T 0 and various p 0 ; 3.Management of the project and dissemination of results.

9. Estimated results:  Flammability parameters for ethylene-air mixtures with various initial concentrations in three asymetrical closed vessels with central ignition at ambient p 0 and T 0 (maximum explosion pressures and times to reach the maximum explosion pressures, maximum rates of pressure rise, propagation velocities);  Flammability parameters for stoichiometric ethylene-air mixtures in three asymetrical closed vessels with central ignition at ambient T 0 and various initial pressures;  Computed adiabatic flammability parameters (adiabatic explosion pressures and adiabatic flame temperatures)  Heat release profiles in stoichiometric ethylene-air flames at various initial pressures.

10. Figura 1- Presiuni de explozie masurate in celula cilindrica avand L/D = 8.1 cu aprindere centrala Figura 2 – Timpii de explozie masurati in celula cilindrica avand L/D = 8.1 cu aprindere centrala Figura 3 – Viteze maxime de crestere a presiunii pentru explozia unor amestecuri etena-aer in celula cilindrica avand L/D = 8.1 cu aprindere centrala Experimental results:

11. Dissemination of project results: 1. C. Movileanu, D. Razus and V. Gosa, Explosion of gaseous ethylene-air mixtures in closed cylindrical vessels with asymmetrical ignition, International Conference of Physical Chemistry - ROMPHYSCHEM 15 th edition: September 11-13, 2013, Bucharest, Romania (Poster); Eighth Mediterranean Combustion Symposium, September 8-13, 2013 Çesme, İzmir, Turkey (Poster); 2. Codina Movileanu, Venera Giurcan, Domnina Razus and Vasile Gosa, Flame propagation in elongated cylindrical vessels with asymmetrical ignition, Eighth Mediterranean Combustion Symposium, September 8-13, 2013 Çesme, İzmir, Turkey (Poster); 3. C. Movileanu, D. Razus, V. Giurcan and V. Gosa, Explosion parameters of gaseous ethylene- air mixtures in elongated cylindrical vessels, PRIOCHEM IX – 24-25 oct. 2013, Bucharest, Romania (Oral communication); 4. C. Movileanu, D. Razus, V. Giurcan and V. Gosa, Experimental and numerical study of ethylene flame propagation in enclosures,French Italian Joint Combustion Meeting: April 23- 24, 2014, Pisa, Italy (Poster); 4. C. Movileanu, D. Razus, V. Giurcan and V. Gosa, Experimental and numerical study of ethylene flame propagation in enclosures, French Italian Joint Combustion Meeting: April 23- 24, 2014, Pisa, Italy (Poster); 5. C. Movileanu, D. Razus, V. Giurcan and V. Gosa, Flame propagation of ethylene-air mixtures in closed tubes, 9th International Colloquium on Pulsed and Continuous Detonations, 18- 24 mai 2014, Puskin, St. Petersburg, Rusia (Oral communication); 6. C. Movileanu, D. Razus, V. Giurcan and V. Gosa, Presssure evolution of ethylene-air explosion in enclosures, XXI Fluid Mechanics Conference, 15-18 iunie 2014 in Cracovia, Polonia (Poster) 6. C. Movileanu, D. Razus, V. Giurcan and V. Gosa, Presssure evolution of ethylene-air explosion in enclosures, XXI Fluid Mechanics Conference, 15-18 iunie 2014 in Cracovia, Polonia (Poster). 7. C. Movileanu, D. Razus, V. Giurcan and V. Gosa, Study of Burning Velocity of Ethylene-Air Flame in Closed Cylindrical Vessels, International Conference on Heat Transfer and Fluid Flow, Prague, Czech Republic, August 11-12, 2014 (Poster).

12. Training of the Project Director: 1. “2013 Princeton Combustion Summer School”, Princeton University, NJ, USA, June 2013. 2. “The Combustion Institute Summer School 2013”, Lund University, Lund Sweden, Aug. 2013.

13. Published papers: - -C. Movileanu, D. Razus, V. Giurcan and V. Gosa, Pressure evolution of ethylene-air explosions in enclosures, J. Physics, Conf. Series, 08/2014, 530(1): 012014. - -C. Movileanu, D. Razus, V. Giurcan and V. Gosa, Flame propagation of ethylene-air mixtures in closed tubes, Proc. Symp. on Pulsed and Continuous Detonations, St. Petersburg, June 2014, pp. 68-72. - -C. Movileanu, D. Razus and V. Gosa, Explosion of gaseous ethylene-air mixtures in closed cylindrical vessels with asymmetrical ignition, submitted to Journal of Hazardous Materials, november 2014.