THE CASE FOR CAVITATION INDUCED HEATING A SUGGESTED MECHANISM
FOR THE HEATING OBSERVED IN CONTROLLED CAVITATION ENERGY STEAM
GENERATION (CCES)
Slide 2
THE CASE FOR MIST AND CAVITATION Energy balance alone cannot
account for the observed levels of heating. Heat output cannot
exceed hydraulic kinetic energy input. Release of hydrogen bonding
energy (23KJ/mole) cannot explain the observed heating.
Electrolysis likely not responsible for observed Oxy Hydrogen
disassociation. Temperatures above 3000 K required for 50% covalent
disassociation. Cavitation is the only (non-nuclear) physical
process capable of generating such heat levels. Where Does the Heat
Come From?
Slide 3
WHAT CAUSES CAVITATION ? CAVITATION OCCURS IF THE LOCAL
PRESSURE DROPS BELOW THE VAPOR PRESSURE OF THE LIQUID AT LOCAL
TEMPERATURES. THE HIGH PRESSURE DROP ACROSS THE INJECTION NOZZLE
TENDS TO ACCELERATE THE LIQUID WITHIN THE SMALL NOZZLE HOLES. THIS
ACCELERATION OF LIQUID INSIDE THE NOZZLE THEREBY GENERATES A HIGH
LEVEL OF TURBULENCE, WHICH HAS AN INSTABILITY EFFECT ON THE JET
LEAVING THE NOZZLE EXIT. AT THE SHARP EDGES INSIDE THE NOZZLE
HOLES, SUCH AS THE INLET OF THE NOZZLE HOLE, THE STREAMLINES ARE
CONTRACTED SUCH THAT THE EFFECTIVE CROSS SECTION OF THE FLOW IS
REDUCED LEADING TO ACCELERATED VELOCITY OF THE LIQUID. ACCORDING TO
BERNOULLI PRINCIPLE, THIS CAUSES A REDUCTION IN THE LOCAL STATIC
PRESSURE AND IT CAN REACH VALUES AS LOW AS THE VAPOR PRESSURE OF
THE LIQUID.
Slide 4
FUEL INJECTORS & CAVITATION Flow inside injection system
and the nozzle is highly unsteady and cavitating Ejection fraction
is saturated with cavitation bubbles Video complement of Fluid
Research - Computational Fluid Dynamic software (CFD).
Slide 5
THEORETICAL BACKGROUND FOR FUEL INJECTOR CAVITATION CAVITATION
IN INJECTOR NOZZLE HOLES - A PARAMETRIC STUDY Balaji Mohan, Wenming
Yang * and Siawkiang Chou Department of Mechanical Engineering,
National University of Singapore, 9 Engineering Drive 1, 117576,
Singapore *E-Mail: [email protected] (Corresponding Author)
ABSTRACT: The fuel injection system in diesel engines has a
consequential effect on the fuel consumption, combustion process
and formation of emissions. Cavitation and turbulence inside a
diesel injector play a critical role in primary spray breakup and
development processes. Thus understanding the phenomenon of
cavitation is significant in capturing the injection process with
accuracy. In this study, the cavitating flow inside an injector
nozzle hole was numerically investigated. The two-phase mixture
model by Schnerr and Sauer (2001) was adopted along with k-
turbulence model and Fluent CFD package was used to solve the
governing equations numerically.
Slide 6
THE ENERGY OF CAVITATION Collapsing cavitation bubbles release
enormous heat energy. Cavitation routinely damages machinery and is
an unwanted side effect. Observation of light pulses emitted by
collapsing cavitation bubbles revealed unexpectedly extreme
conditions within the collapsing bubble cores. Temperatures in
excess of 30,000K (5 times hotter than the surface of the sun) have
been measured directly and even higher Temperatures (in millions
degrees K) have been inferred (Flannigan & Suslick, 2010).
Cavitation damage is most commonly observed in rotating machinery.
Impellers, propellers and turbines. Significant engineering
resources have been applied towards eliminating this type of
damage; however there has never been a practical way of harnessing
this energy, although vast funds of have been invested to a
accomplish this result with no practical outcome. (UNTIL THE ADVENT
OF MIST)
Slide 7
WHAT HAPPENS WHEN THE EJECTION FRACTION COLLIDES WITH THE
IMPACT CHAMBER SURFACE The gas bubble in the expanding cloud of
injector vapor collides with the Surface geometry of the impact
chamber The impact chamber is very close to the output of the
injector The cloud of bubbles within the water droplet impacts the
surface of the impact chamber normal to its surface. At the moment
of impact the droplet experiences a shockwave with a rapidly moving
shock front. Within the droplet computed and observed water hammer
pressures on the order of (45,000 psi) crushes these bubbles. As
they collapse energy is released. Super computing record with
bubble collapse simulation
Slide 8
IMPACT CHAMBER GEOMETRIES ESSENTIAL AND ENERGIES RELEASED
CONSIDERABLE Hong-Hui et al. (Wear 186-187 (1995)) Found that
impact pressures for hypersonic water jets were Dependent on
distance and angle of impact. The kinetic energy of the implosion
grows as a cube of the maximum bubble radius Rmax: E = 4/3 Rmax3
Pmax (1) where Rmax is the maximum bubble radius and Pmax is
theliquid pressure during the collapse phase (constant pressure is
assumed). What makes this energy concentrating process useful is
that this energy can be focused onto a minuscule amount of gas
trapped in the initially small (micron-size) gas bubble.From the
equation of state for an ideal gas: P0 V0 = N kB T0 (2) where P0
initial bubble gas pressure, V0 = 4/3 R03 is the initial bubble
volume, N number of atoms of gas in the bubble, kB Bolzmann
constant, T0 initial bubble gas temperature, we can estimate
maximum energy concentration per atom of gas (Ea) as Ea = (kB T0)-1
(Rmax/R0)3 Pmax/P0
Slide 9
THE INITIAL EVIDENCE DURING OUR FIRST TESTS HEAT INCREASED FROM
375 DEGREES F TO 575 DEGREES F IN 2 SECONDS. INSTANTANEOUS CHANGE
OF STATE FROM LIQUID TO GAS IN MILLISECONDS
Slide 10
OUR EXPERIMENTAL EVIDENCE CONFIRMS THIS Oxy-hydrogen explosions
at 900 psi and 620 degrees F
Slide 11
CONTROLLING CAVITATION IS THE KEY TO OUR ENERGY FUTURE No
commercial inventions exist that functionally harness cavitation
MIST is the only system capable of instantaneously producing steam
on demand with significantly less energy than conventional Rankine
Cycle heating Cavitation is the only way to generates these
temperatures short of Low Energy Nuclear Reactions (LENR) CCES is
the only steam based system which creates a usable source of energy
through a mechanical process rather than internal or external
combustion. CCES uses modern technologies only now available that
are financially viable (ie. Common rail piezo injectors, computer
Controllers, ultra high pressure pumps, carbon fiber and ceramics)
CCES impacts almost every aspect of modern living. Power
generation, transportation, desalination, heating, refrigeration,
shipping