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Effect of Magnetic Fields on Fire Katsuo Maxted Aviation Fire Dynamics March 15, 2013.

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Presentation on theme: "Effect of Magnetic Fields on Fire Katsuo Maxted Aviation Fire Dynamics March 15, 2013."— Presentation transcript:

1 Effect of Magnetic Fields on Fire Katsuo Maxted Aviation Fire Dynamics March 15, 2013

2 Outline Introduction Magnetic Properties in Combustion Magnetic Confinement Fusion Magnetic Induction in a Plasma Torch Modeling Affects on a Diffusion Flame Benefits Using Magnetism

3 Introduction Magnetism Defined as the phenomena that accounts to forces exerted by magnets Depends on other magnetic fields, temperature, and pressure

4 Introduction NS Types of Magnets Ferromagnets are permanent and have the strongest influence.

5 Introduction NS Types of Magnets Paramagnets are temporary magnets that created from an applied magnetic field N S

6 Introduction Types of Magnets Diamagnets are the weakest magnets that exhibit an opposing magnetic field to an applied one NS S N

7 Introduction Types of Magnets Electromagnets are magnets composed of wires carrying an electric current NS

8 Introduction Bio-magnetics [1] Magnetic Resonance Imaging (MRI) Enhance Combustion Processes Magnetic Fields have been applied in:

9 Introduction Units are in T (Tesla) for strength and T/m (Tesla per meter) for intensity Refer to magnetic gradient for multiple field lines Paramagnetism, Ferromagnetism, & Diamagnetism

10 Introduction Oxygen is known for its paramagnetism Nitrogen, Carbon Dioxide, and most hydrocarbon fuels are repelled because of their diamagnetic nature [2, 3] Magnetic field affects all gases:

11 Outline Introduction Magnetic Properties in Combustion Magnetic Confinement Fusion Magnetic Induction in a Plasma Torch Modeling Affects on a Diffusion Flame Benefits Using Magnetism

12 Magnetic Properties In the presence of an external magnetic field, a flame on wax paper forms an equatorial disk and is more luminous Faraday attributed this to deflection of charged particles from the flame Von Engel & Cozens said deflection is caused by diamagnetic gases Background [4, 5, 6]

13 Magnetic Properties For highly conductive fluids like plasma and salt water, Lenz’s law indicates that a charged fluid will follow the direction of a magnetically induced electromotive force Magnetic field lines perpendicular to fluid flow direction increase it’s speed while parallel magnetic fields do the opposite [2] Effect on Fluid Flow

14 Magnetic Properties Effects in Chemical Reactions Spin (S) indicates the angular momentum of a charged particle The multiplicity or overall spin of a molecule is defined as 2S + 1 where S = ½*(number of unpaired electrons) Maxwell’s theory states that a moving charged particle creates a magnetic moment, indicating that a higher spin generates a stronger magnetic moment

15 Magnetic Properties Effects in Chemical Reactions [7] Oxygen gas (which is in a singlet state) must be broken into triplets before becoming paramagnetic Radicals are paramagnetic with a spin S = ½ Diamagnetic effects cause radicals to form in pairs, causing doublets to excite to triplets, and after reaction, spins are conserved from diamagnetic predecessors

16 Magnetic Properties Effects in Chemical Reactions [7] Magnetic control on spin Four spin states: exchange interaction, electron spin-dipolar interaction, hyperfine interaction and Zeeman interaction

17 Magnetic Properties Effects in Chemical Reactions Example: Photochemical Process [8] Stationary temperature dependence of the reacting system on external radiation value in the presence and in the absence of magnetic field

18 Magnetic Properties Effects in Chemical Reactions Example: Photochemical Process [8] Stationary concentration dependence of biradicals on external radiation value in the presence and in the absence of magnetic field

19 Magnetic Properties Magnetic field Intensity of 1 T is said to alter combustion characteristics [3, 9] Production of 1 T rare-earth magnets can replace the need for electromagnets [10, 11]

20 Magnetic Properties Oxygen has randomly oriented dipole moments that align with the applied field Nitrogen, Carbon Dioxide and most hydrocarbon fuels form a net dipole moment in opposition to the applied field Dipole alignment

21 Magnetic Properties First Regime - At low velocities, gas flow is diffused through the magnetic curtain. Second Regime - At slightly higher flow velocities, gas flow is blocked at the highest magnetic field gradient Third Regime - At higher flow rates, the gas flow is allowed to pass though curtain in a pinched fashion Three Regimes for blocking gas flow [12]: Magnetic fields do not separate nitrogen and oxygen Magnetic fields do not separate nitrogen and oxygen!

22 Magnetic Properties Application of magnetic field gradients of T/m under T decreased combustion temperature from 200 to 100 ˚C Combustion rate decreased for location of highest magnetic field strength Candle flame, hydrogen flame and methane flame are also deflected toward lesser magnetic field strengths For combustion of alchohol [1, 2]

23 Magnetic Properties Candle flame can be quenched between two cylindrical electromagnets when interacting with a field strength of 1.5 T and intensity gradient of T/m in a 5-10 mm space Flame is not quenched below 0.9 T Flame Quenching [3]

24 Magnetic Properties Magnetic field near reaction zone greatly increases emission intensity Cleaner burning - soot levels are decreased Radiative Emissions from Diffusion Flames [13]

25 Magnetic Properties Larger influence on diffusion flames due to buoyancy induced convective air flow Longer burning periods on diffusion flames Affects flame shape without pressurized containments Studies in Microgravity [14, 15, 16]

26 Magnetic Properties In microgravity, the magnetic field causes the flame to behave like it’s subjected to buoyant forces (which can be isolated in normal gravity) Large soot particles can be decreased Studies in Microgravity [14, 15, 16]

27 Magnetic Properties Uniform Magnetic field produces no observable change Combustion is enhanced in the presence of a decreasing magnetic field Ferromagnets are ideal for experimentation due to the absence of Ampere and Lorenz forces Summary

28 Outline Introduction Magnetic Properties in Combustion Magnetic Confinement Fusion Magnetic Induction in a Plasma Torch Modeling Affects on a Diffusion Flame Benefits Using Magnetism

29 Magnetic Confinement Fusion Plasma in Relation to Fire Plasma is defined as a quasineutral gas composed of charged and neutral particles The ‘reaction zone’ of a diffusion flame at high pressure may be characterized as a plasma

30 Magnetic Confinement Fusion Stellarator Toroidal Tokamak Spherical Tokamak

31 Magnetic Confinement Fusion Stellarator [17] QPS Coil-sets and plasma. Modular coils are shown in light blue, toroidal field coils are pink, vertical field coils are in tan. Color contours (blue = low field, red = high field) show the magnetic field strength on the outer plasma magnetic flux surface

32 Magnetic Confinement Fusion Toroidal Tokamak [18]

33 33 Magnetic Confinement Fusion Spherical Tokamak [19]

34 Outline Introduction Magnetic Properties in Combustion Magnetic Confinement Fusion Magnetic Induction in a Plasma Torch Modeling Affects on a Diffusion Flame Benefits Using Magnetism

35 Plasma Torch [20] Hybrid (RF + DC) plasma torch

36 Plasma Torch [20] Direct Current Induction Includes anodes, cathode and gas inlets

37 Plasma Torch [20] Radio-frequency Induction Advantages: large volume plasma generation; cleanness; simplicity; easy in-feeding into plasma; long lifecycle Includes metal water- cooling sections; quarts tube; body corpus and gas former

38 Plasma Torch [20]

39

40 Outline Introduction Magnetic Properties in Combustion Magnetic Confinement Fusion Magnetic Induction in a Plasma Torch Modeling Affects on a Diffusion Flame Benefits Using Magnetism

41 Affects on Diffusion Flame [21]

42 Evolution of the temperature along the flame axis, lift-off height and flame length with the injection velocity of air in the presence of a magnetic field(MF) and without magnetic field(WMF) for two injection velocities of CH4: 0.54(a) and 0.79(d) for a position of the burner Z = +85mm.

43 Affects on Diffusion Flame [21] Evolution of the visual lift-off height with the injection velocity of air in the presence of a magnetic field (MF) and without magnetic field (WMF) for two injection velocities of CH4: 0.54 and 0.79 m/s for a position of the burner Z = - 185mm.

44 Affects on Diffusion Flame [21]

45 Analysis Magnetic fields of decreasing strength lengthen lift-off height and accelerate normal convection Thermo-magnetic convection slows normal convection for fields of increasing strength

46 Field Modeling Solenoid (hollow) Diffusion Flame Magnetic Field Lines

47 Field Modeling Geometry 0 Coil

48 Field Modeling Biot-Savart Law

49 Field Modeling Biot-Savart Law

50 Field Modeling Biot-Savart Law

51 Field Modeling Biot-Savart Law Magnetic field vector in 3D space is determined by the addition of two integrals for two coils. Ends of solenoids are connected with a sinusoidal function The connectors distort magnetic fields lines so data was taken away from the connectors

52 Field Modeling

53 Observations Magnetic fields lines running through the outer regions of the electromagnets are unpredictable and highly sensitive to initial conditions Field lines not affected by chaos slightly deviate from their initial linear paths when between magnets

54 Conclusions More coil windings (and hence a stronger magnetic field) give straighter magnetic field lines between the two solenoids, giving the flame an increased linear stability A longer flame length is due to the stronger influence from the central area of an electromagnet Flame behavior in outer regions of electromagnets is unpredictable

55 Outline Introduction Magnetic Properties in Combustion Magnetic Confinement Fusion Magnetic Induction in a Plasma Torch Magnetic Field Line Modeling Benefits Using Magnetism

56 Fire Suppression Fire scan be suppressed through electromagnetic pulses, which is an environmentally friendly alternative for water and chemicals Pulses are meant to scatter gases necessary for reactions to take place. Not applicable to large scale fires!

57 Applications Useful for entraining oxygen in microgravity environments Flame stabilization in combustion engines Experimental research in plasma assisted combustion

58 References [1] S. Ueno and K. Harada, “Experimental Difficulties in Observing the Effects of Magnetic Fields on Biological and Chemical Processes”, IEEE Transactions on Magnetics, Vol. MAG-22, No.5, September 1986, pp [2] S. Ueno and K. Harada, “Effects of Magnetic Fields on Flames and Gas Flow”, IEEE Transactions on Magnetics, Vol. MAG-23, No.5, September 1987, pp [3] S. Ueno, “Quenching of Flames by Magnetic Fields”, Journal of Applied Physics, Vol. 65, No. 3, February 1989, pp [4] Prof. Zantedeschi, “ On the Motions Presented by Flame when under the Electro-Magnetic Influence”, The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, Series 3, Vol. 31, No. 210, December 1847, pp [5] M. Faraday, “ On the Diamagnetic Conditions of Flame and Gases”, The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, Series 3, Vol. 31, No. 210, December 1847, pp [6] A. V. Engle and J. R. Cozens, “Flame Plasmas,” Advances in Electronics and Electron Physics, Vol. 20, 1964, pp [7] U. E. Steiner, “Spin Chemistry: how magnetic fields affect chemical reactions”, Summer School on Magnetic Fields in Science, University of Konstanz, Cargese, Corsica, Received from cargese.grenoble.cnrs.fr/Steiner_Abstract.pdf.

59 References [8] A. A. Kipriyanov (Jr.), P. A. Purtov, “Magnetic field effects on chemical reactions near the disturbance of stationary states conditions”, Chaotic Modeling and Simulation (CMSIM) 1: 53-65, 2012 [9] T. Aoki, “Radicals’ Emissions and Butane Diffusion Flames Exposed to Upward Decreasing Magnetic Fields,” Japanese Journal of Applied Physics, Vol. 28, 1989, pp [10] J. Baker, M. E. Calvert, K. Saito and R. Vander Wal, “Holographic Interferometry and Laminar Jet Diffusion Flames in the Presence of Non-Uniform Magnetic Fields”, Sixth International Microgravity Conference, 2001, pp [11] J. Baker, M.E. Calvert, K. Saito and R. Vander Wal, “An Analytical Model for Non-Uniform Magnetic Field Effects on Two-Dimensional Laminar Jet Diffusion Flames”, Sixth International Microgravity Conference, 2001, pp [12] S. Ueno and M. Iwasaka, “Properties of Magnetic Curtain Produced by Magnetic fields”, Journal of Applied Physics, Vol. 67, No. 9, May 1990, pp [13] N. I. Wakayama, “Effect of a Gradient Magnetic Field on the Combustion of Methane in Air”, Chemical Physics Letters, Vol. 188, No. 3, Jan. 1992, pp [14] N. I. Wakayama, “Magnetic Support of Combustion in Diffusion Flames under Microgravity”, Combustion and Flame, Vol. 107, 1996, pp

60 References [15] N. I. Wakayama, “Utilization of Magnetic Force in Space Experiments”, Advances in Space Research, Vol. 24, No. 10, 1999, pp [16] F. Khaldi, K. Messadek, A. M. Benselama, “Isolation of Gravity Effects on Diffusion Flames by Magnetic Field”, Microgravity Sci. Technology (2010) 22:1-5. [17] D. A. Spong, D. J. Strickler, S. P. Hirshman, J. F. Lyon, L. A. Berry, D. Mikkelsen, D. Monticello, A. S. Ware, “confinement physics and flow damping in quasi-poloidal stellarators”, The 14 th International Stellarator Workshop, Griefswald, Germany, [18] Picture received from [19] World Nuclear Association, Ian Hore-Lacy (Lead Author);PPPL (Content Source);Cutler J. Cleveland (Topic Editor) "Nuclear fusion power". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth December 6, 2009; Last revised Date December 6, 2009; Retrieved March 14, 2013 World Nuclear Associationr);PPPL (Contclear fusion power" [20] V. Frolov, I. Matveev, D. Ivanov, S. Zverev, B. Ushin, G. Petrov, “experimental investigations of the hybrid plasma torch with reverse vortex stabilization “, Applied Plasma Technologies, 1729 Court Petit, McLean, VA 22101, USA. Received from V. Frolov, I. Matveev, D. Ivanov, S. Zverev, B. U [21] M. Chahine, P. Gillon, B. Sarh, J. N. Blanchard, V. Gilard, “Magnetic Field Effect on Methane/Air Diffusion Flame Characteristics”, Universite d’Orleans, 16 Rue d’Issoudun – BP Orleans cedex 2, France. Received from 0.pdf.

61 Fin


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