Sally Bane
Assistant Professor of Aeronautics and Astronautics
Telephone: (765) 494-9364
Email: sbane@purdue.edu
More about Sally Bane
Graduate Students
Tyler Graziano
School: Aeronautics and Astronautics
Graduated: 2016
Project/Thesis: Development of Combustion Tube for Gaseous, Liquid, and Solid Fuels to Study Flame Acceleration and DDT
Angela Mbugua
School: Aeronautics and Astronautics
Graduated: 2019
Project/Thesis: Characterization of Ignition and Combustion of Nitromethane and Isopropyl Nitrate Monopropellant Droplets
Steven Stoot
School: Aeronautics and Astronautics
Graduated: 2015
Project/Thesis: Combustion Characteristics of Hypergolic Microdroplets
Prashanth Bangalore Venkatesh
School: Aeronautics and Astronautics
Graduated: 2019
Project/Thesis: High Pressure Combustion in C2H4/N2O Mixtures Leading to Detonations and its Applications
Recent Publications
Investigation of the effect of electrode geometry on spark ignition
Bane, Sally P.M ; Ziegler, Jack L ; Shepherd, Joseph E
Combustion and Flame, February 2015, Vol.162(2), pp.462-469
Abstract
High-speed schlieren visualization and numerical simulations are used to study the fluid mechanics following a spark discharge and the effect on the ignition process in a hydrogen–air mixture. A two-dimensional axisymmetric model of spark discharge in air and spark ignition was developed using the non-reactive and reactive Navier–Stokes equations including mass and heat diffusion. The numerical method employs structured adaptive mesh refinement software to produce highly-resolved simulations, which is critical for accurate resolution of all the physical scales of the complex fluid mechanics and chemistry. The simulations were performed with three different electrode geometries to investigate the effect of the geometry on the fluid mechanics of the evolving spark kernel and on flame formation. The computational results were compared with high-speed schlieren visualization of spark and ignition kernels. It was shown that the spark channel emits a blast wave that is spherical near the electrode surfaces and cylindrical near the center of the spark gap, and thus is highly influenced by the electrode geometry. The ensuing competition between spherical and cylindrical expansion in the spark gap and the boundary layer on the electrode surface both generate vorticity, resulting in the toroidal shape of the hot gas kernel and enhanced mixing. The temperature and rate of cooling of the hot kernel and mixing region are significantly effected by the electrode geometry and will have a critical impact on ignition. In the flanged electrode configuration the viscous effects generate a multidimensional flow field and lead to a curved flame front, a result not seen in previous work. Also, the high level of confinement by the flanges results in higher gas temperatures, suggesting that a lower ignition energy would be required. The results of this work provide new insights on the roles of the various physical phenomena in spark kernel formation and ignition, in particular the important effects of viscosity, pressure gradients, electrode geometry, and hot gas confinement.
Bipropellant high energy stimulation for oil and gas applications
Bangalore Venkatesh, Prashanth ; D'Entremont, James H ; Meyer, Scott E ; Bane, Sally P.M ; Grubelich, Mark C ; King, Dennis K
Journal of Petroleum Science and Engineering, September 2019, Vol.180, pp.660-667
Abstract
Large-scale extraction of oil and natural gas requires an effective method of generating a high surface area network of fractures, or the stimulation of existing fractures, in a formation in order to increase permeability. Conventional hydraulic fracturing has limited utility in this application. In this work, Sandia National Laboratories is exploring high rate pressurization techniques employing tailored energetic materials systems to control both pressure rise rate and peak pressure in order to optimally stimulate potential rock formations. Rapid pressurization, at rates far exceeding quasi-static conventional hydraulic rates, can generate multiple radial well bore fractures and potentially provide a mechanism to induce shear destabilization within the formation that enables the fractures to be self-propping. Multiple fractures from the well bore allow efficient coupling to the existing formation fracture network and increase near field well bore permeability. Furthermore, these techniques can allow for repeated stimulations and produce energetic events within the fractures thereby allowing fractures to be extended further. Controlled rate pressurization is a useful tool for the efficient generation of fracture networks and has potential application to increase oil and gas production. This paper provides an overview of the concept of controlled rate pressurization, laboratory experiments and field trials that are being conducted. The present work investigates detonations of a stoichiometric mixture of ethylene and nitrous oxide (C2H4 + 6N2O) at high initial pressures ranging from 0.862 to 2.068 MPa as a method of fracturing rock below the ground surface. The experiments investigate the fracture generation as a function of the initial pressure of the mixture. In the current configuration, the combustion reaction is initiated by an electrically fired igniter at the ground surface and quickly transitions to a detonation. The experimental setup accommodates one high pressure (690 MPa) transducer, placed downstream of the igniter, to measure peak pressure. The pressure transducer recorded peak pressures, which are 2.3–2.6 times in excess of the Chapman-Jouguet (CJ) values as a result of pre-compression of the unburned gas mixture during the flame acceleration prior to deflagration-to-detonation transition (DDT). Analysis of the data indicated an increase in rock permeability due to detonations and this was confirmed by the core drilled sections at the test site.
Deflagration-to-Detonation Transition in Nitrous Oxide/Oxygen-Fuel Mixtures for Propulsion
Meyer, Scott ; Bane, Sally ; Grubelich, Mark
Journal of Propulsion and Power, Sep/Oct 2019, Vol.35(5), pp.944-952
Abstract
Nitrous oxide (N2O) has gained popularity as a unique oxidizer for propulsion applications due to its ability to decompose exothermically, producing nitrogen and oxygen. In the current work, the flame acceleration, deflagration-to-detonation transition, and detonation properties of bipropellant mixtures with N2O as the oxidizer are studied for potential applications in pulsed blowdown and detonation-driven thrusters. These properties are compared with those in mixtures with oxygen (O2) or nitrogen tetroxide (N2O4) as the oxidizer. The performance of N2O versus O2/N2O4 for detonation engine applications is investigated using theoretical Chapman–Jouguet detonation calculations of bipropellant systems with ethylene (C2H4) and acetylene (C2H2) as fuels. A critical requirement for the application of bipropellant mixtures to pulsed propulsion systems is rapid flame acceleration to achieve significant chamber pressure rise in a short distance with the potential for a prompt transition to detonation. This deflagration-to-detonation transition behavior of mixtures using C2H4 and C2H2 with N2O and O2 is investigated for increasing initial pressures in the experimental portion of this work. While C2H2 is a highly energetic fuel with theoretically high performance, it presents serious practical storage concerns when considered for propulsion applications. These practical issues motivate investigation of C2H4 as a potential alternative fuel, which is relatively easy to manage. The precompression of the bipropellant mixtures during flame acceleration is also estimated and compared.
Ignition and combustion characterization of single nitromethane and isopropyl nitrate monopropellant droplets under high-temperature and quasi-steady conditions
Mbugua, Angela ; Satija, Aman ; Lucht, Robert P ; Bane, Sally
Combustion and Flame, February 2020, Vol.212, pp.295-308
Abstract
The dynamics of reacting droplets of the monopropellants nitromethane (NM) and isopropyl nitrate (IPN) are compared to those of methanol. Single droplets of these three fuels were burned in steady flow high-temperature conditions, produced by a McKenna flat-flame burner. Coherent anti-Stokes Raman scattering (CARS) thermometry was employed to characterize the temperature of the flow-field experienced by the droplets. Ignition delay times and droplet burning rates were obtained for droplets with initial diameters ranging between 0.4 and 1.4 mm. Droplet dynamics such as deformation, puffing, stripping and micro-explosions are qualitatively discussed. Lastly, the D2 law and the hybrid combustion model are applied to IPN and NM droplets, and the experimental mass burning rates are compared to theoretical predictions.