Neil Glikin Microgravity Project
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Transcript of Neil Glikin Microgravity Project
Neil Glikin
B.S. Mechanical Engineering, Physics
University of Florida, 2015
Principal Investigator:
Team Leads:
Team Members:
Dr. Jacob N. Chung
Neil Glikin
Samuel Darr
Christian Ball
Chase Camarotti
Oscar Deng
Jun Dong
Kenton Prescott
• Overview
• Experiment Background
• Design Requirements
• Apparatus Summary
• Pressure Vessel System Design
• Structural Design and Analysis
• Construction
Contents
Overview
This presentation provides a summary of
the design and manufacturing of a novel,
complex experimental apparatus designed
for safe management of cryogenic fluid
and structural integrity aboard NASA’s C-
9B reduced gravity aircraft, while meeting
experimental parameter requirements.
Experiment Background
0 20 40 60 80 100 12050
100
150
200
250
300
Time, s
Pip
e W
all T
em
pera
ture
, K
Downward, Ress
= 6,014
Downward, Ress
= 34,863
Downward, Ress
= 167,086
Upward, Ress
= 6,090
Upward, Ress
= 32,812
Upward, Ress
= 171,121
Why study liquid nitrogen chilldown?
The transient process of cooling a pipe or tube with a cryogenic fluid is a commonly
encountered process in cryogenic rocket propulsion systems, but it is not fully understood.
Knowledge of the chilldown rate will tell cryogenic propulsion systems designers how
much time and how much expended propellant will be required by their systems during
engine startup and propellant transfer.
Why microgravity?
The plot to the right demonstrates the
effect that gravity has on such chilldown
processes in a 1-g environment. At high
steady-state Reynolds numbers (Ress),
upward and downward flows have little
difference in chilldown time, while at low
Ress, the effects of gravity are
considerable. This makes experiments in
microgravity conditions imperative to
understanding chilldown in space.
Design Requirements
Experimental
• Chill down a stainless steel tube,
beginning at room temperature, to
liquid nitrogen (LN2) temperatures.
• Set boundary conditions such that
incoming liquid is subcooled and heat
transfer is only between the liquid and
the tube.
• Conduct enough tests to achieve a
range of fluid pressures of 100 – 700
kPa and a range of Reynolds
numbers of 20,000 – 250,000.
• Measure temperature, pressure, and
mass flow rate of liquid flow in time.
For flight readiness
• No external surface warmer than 50 °C
or colder than 5 °C.
• All cryogenic fluid contained within a
pressure vessel system. All flowing
liquid vaporized and vented overboard
at a temperature of no lower than 0 °C.
• Ensure entire pressure vessel system
can handle maximum expected
pressures within a safety factor of 2.
• No material yielding within a safety
factor of 2 for six different defined
emergency landing scenarios.
The apparatus was designed to meet both the experimental requirements of
the research and the safety and readiness requirements of the C-9B aircraft.
Apparatus Summary Frame
Constructed
primarily from
80/20 aluminum
bars. Fastens to
floor of airplane
and holds all
components.
Dewar
Stores and
pressurizes
liquid nitrogen.
Precooler
Surrounds
incoming liquid
with an
insulating
vessel of liquid
nitrogen.
Vacuum
Chamber
Surrounds the
test section,
where
measurements
are taken, in
order to
minimize heat
transfer with
surrounding
air.
Vaporizers
Vaporize all flowing liquid nitrogen and heat the
vapor to above 0 °C within only 2.5 feet of length.
Liquid flow
from dewar
Vaporized
flow to
overboard
vent
3 ft
Pressure Vessel System DesignPrecooler
• Insulates liquid traveling through the
transfer pipe by surrounding it with
stored low-pressure liquid nitrogen.
• Can withstand over 200 psi of
pressure, well above the maximum
experimental pressure of 100 psi.
Vaporizers
• Designed to be a highly efficient heat
source for vaporizing liquid nitrogen in
a compact space. Heated by
externally wrapped heating cable.
• Provide 80 kW of power to vaporize
all liquid nitrogen at flow rates of up to
8 L/min.
Structural Design and AnalysisThe apparatus, particularly the
frame, was designed to
withstand any of the emergency
landing scenarios.
A comprehensive structural
analysis was carried out to
demonstrate the structural
integrity of the entire apparatus.
Free-body diagrams were used
to solve for reaction forces from
the frame onto all of the major
components of the apparatus.
Example: Free-body diagram of the dewar in
the emergency landing scenario of 9 g’s of
load in the forward direction of the plane.
The reaction forces were used as boundary conditions to simulate the stresses
and strains in the frame using ANSYS.
The frame consists of over 100 joints and over 500 fasteners. Each was
chosen in order to withstand the joint loads predicted by the simulation.
Structural Design and Analysis
Construction: In Progress
The precooler and other components are surrounded by ice when not insulated.
Themocouples are being used to test the operation of the vaporizers.
i
Construction: Complete
Insulation surrounds all hot and cold surfaces. All
components are secured onto the frame.