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.

Thank you!

Neil Glikin

[email protected]

813-767-6532