• Version
• 100 Downloads
• 2.61 MB File Size
• 1 File Count
• December 4, 2015 Create Date
• December 4, 2015 Last Updated

National Advisory Committee for Aeronautics, Report - NACA Research on Slurry Fuels

An extensive program was conducted to investigate the use of
concentrated slurries of boron and magnesium in liquid hydro-
carbon as fuels for afterburners and ramjet engines. Analytical
calculations indicated that magnesium fuel would give greater
thrust and that boron fuel would give greater range than/are ob-
tainable from jet hydrocarbon fuel alone. It was hoped that
the use of these solid elements in slum-y form would permit the
improvement to be obtained without requiring unconventional
fuel systems or combustors.

Slurries consisting of 50 percent or more magnesium or
boron in JP fuels were prepared, although it was dizficult to
obtain successive batches with uniform properties. A vaporiza-
tion process was devised for the preparation of very finely
divided magnesium. The storage stability, spray characteris—
tics, and non-Newtonian flow behavior of the slurries varied
with the particle size of the metal and the type and concentration
of the additives incorporated. The storage stability was limited
to 6‘ months or less, but some types of magnesium slurries could
readily be reconstituted by muting. Slurry fuels formed coarser
sprays than jet hydrocarbon fuel did. ‘

Tests in pipe-connected combustors of various designs shmed
that slurried magnesium burned very readily even under condi-
tions where jet hydrocarbon fuel itself would not burn, and the
expected improvement in thrust was obtained. Data from tests
on afterburners indicated that coolant injection would accentuate
the improvement. However, some modification of conventional
fuel systems and combustors was required to compensate for the
diference inflow properties between jet hydrocarbon and slurry
fuels.

Small ramjet vehicles fueled un'th magnesium slwry were
flown successfully, but the test flights indicated that further
improvement of combustors and fuel systems was needed.

In contrast to the favorable results with magnesium slurn'es,
the boron slurries that were prepared were more diflicult to burn.
than conventional jet fuel and formed objectionable deposits in
the combustor.