University of Notre Dame Particle Dynamics Laboratory Michael P. Davis and Patrick F. Dunn Department of Aerospace and Mechanical Engineering Particle Dynamics Laboratory B032 Hessert Laboratory University of Notre Dame Notre Dame, IN USA University of Notre Dame AME - Graduate Student Conference October 19, 2006 SPONSOR: Honeywell International, Incorporated Jet Fuel Cavitation in a Converging- Diverging Nozzle

University of Notre Dame Particle Dynamics Laboratory Brennan (1995). Cavitation - “the process of rupturing a liquid by decrease in pressure at roughly constant liquid temperature” FLUENT simulation Cavitation Fundamentals

University of Notre Dame Particle Dynamics Laboratory Motivation - Honeywell Fuel Pump Honeywell product line includes valves, flow controllers, and fuel pumps Common to all devices is high flow rates through very small orifices, resulting in cavitation Presence of bubbles causes damage to components, vibrations, and a loss of pump efficiency pitting damage caused by cavitation

University of Notre Dame Particle Dynamics Laboratory spherical bubbles slug-like gas voids bubbly shock microbubble nuclei originating from microparticles or walls liquid solid gas pockets x flow Void Fraction = f(x) Pressure = f(x) Void Fraction = Gas Volume/Total Volume Problem Description

University of Notre Dame Particle Dynamics Laboratory bubble interface, surface tension far field, bubble inertia bubble contents far field pressure in liquid surface tension viscous effects - fluid density - fluid viscosity Vapor + Gas R(t) Bubble Dynamics - Raleigh Plesset Equation

University of Notre Dame Particle Dynamics Laboratory Raleigh-Plesset in a C-D Nozzle (continuity) (momentum) (bubble dynamics) (void fraction) (viscosity) (pressure forcing) (surface tension) (liquid tension)

University of Notre Dame Particle Dynamics Laboratory Transducers measure  P Experimental Apparatus

University of Notre Dame Particle Dynamics Laboratory

flow JP-8 H2OH2O

University of Notre Dame Particle Dynamics Laboratory Void Fraction by Laser Light Scattering Initialize counter and increment each time voltage drops below threshold Compute running average as a function of time and look for convergence Need a way to calibrate output signal Flow direction V out = f(  Running average Test section Cavitation Bubbles Photo-diode array HeNe laser

University of Notre Dame Particle Dynamics Laboratory flow

University of Notre Dame Particle Dynamics Laboratory flow

University of Notre Dame Particle Dynamics Laboratory flow JP-8 H2OH2O

University of Notre Dame Particle Dynamics Laboratory The experimentally determined JP-8 mass flux under choked conditions can be used to identify the maximum volumetric flow rates achievable for a given minimum flow cross-sectional area assuming similar, fully choked flow conditions. Maximum Flow Rate Estimate

University of Notre Dame Particle Dynamics Laboratory Reliably predict cavitation in internal flows involving hydrocarbon fuels. Obtain experimental void fraction and pressure profiles for model comparison. Parallel experimental and computational approach is focused on model development. Development of passive and active cavitation control strategies. Goals of Research - Summary