TrimSolutions software is

foamyflumpMobile - Wireless

Nov 21, 2013 (3 years and 6 months ago)

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SpaceForest

is
located

in
the
Pomeranian

Science &
Technology Park (PPNT)
in

Gdynia (
www.spaceforest.pl
)

SpaceForest

creates

and

actively

explores

innovative

ideas
.

Our

company

specializes

in

Artificial

Intelligence

(AI)

and

Video

Recognition

(VR
)

solutions
,

which

are

used

in

optimization

of

industrial

processes
.

SpaceForest

works

on

diverse

tasks

in

many

different

areas

of

engineering

related

to

e
lectronics
,

IT

and

s
pace
-
t
ech
.

the software for post
-
production computer aided
tuning of microwave filters

TrimSolutions software is
applicable
in

tuning of

very high frequency
telecommunication single and
multimode
satellite
filters

up to
Ka band

(40
GHz
)

2013 SpaceForest Ltd.


All rights reserved.

Purpose

of building a rocket


Call
:

ARTEMIS


2013
;


European Commission



Project:

DEWI

Dependable Embedded Wireless




I
nfrastructure


(3rd place of 22 Artemis
projects
)


Business
Needs
:
R
educ
tion

of
aircraft
weight

by removing wires


and using
WSN

(
Wireless Sensor Network
)



Domain
:

AERONAUTICS

aeroplanes
,
helicopters
,
launchers


Example
:
t
he
Ariane

5

telemetry

system
contains

of

600 to 800
sensors. Telemetry
system
control

unit
is

centralized. Thousands of
cables
are

spread all over the 40 meter

launcher
.




70 % of
Ariane

5 avionics mass are cables
.

2013 SpaceForest Ltd.


All rights reserved.

Purpose

of building a rocket


U
se

C
ase
:
MTL

(
Multilink Telemetry Logger
)

in Space Test
,
supported

by

Spain


Demonstrator:
TEST ROCKET

SpaceForest

as
the

lead

partner



D
emonstrator

of outcomes of the project


a
test

rocket
proposed by
SpaceForest

-

was very well received.

Large

of
the

needed
demonstrator
propulsion
:


100
[
kNs
]

of engine total impulse
,


1 [Ton]

of
thrust


~50 [kg]

of
burned

propellant


2013 SpaceForest Ltd.


All rights reserved.

Why hybrid propulsion?


Advantages

(i
n comparison to solid rocket engines
)
:

-

F
ully

legal regarding to the Polish law. This kind of engine is not a



pyrotechnic or explosive material
.

R&D activities are not restricted
.

-

I
ncreased

personnel safety
.

-

P
ossibility

of thrust control
.

-

P
ossibility

of emergency shut down
.







figure

made

by Paweł Surmacz

Disadvantages:

-

M
ore complicated
.

-

L
ower

oxidizer and fuel density
.

-

B
igger

propulsion
system
volume
.

-

O
xidizer

losses during the rocket
tank
fueling
.

2013 SpaceForest Ltd.


All rights reserved.

Our

choice

Nitrous Oxide N
2
O as oxidizer


Advantages:

-

relatively inexpensive and available on the market
,

-

easy storable in normal conditions
,

-

auto
-
pressurized
51
[
bar
]

@ 20
0


(
extrusion system not needed
),

-

non
-
toxic
,

-

possibility to use typical materials like


aluminum, stainless steel,
T
eflon
.


Disadvantages:

-

pressure tank needed (large mass)
,

-

low density
of
the liquid phase


0,786
[
kg/dm
3
]

@ 20
0
C
only
,

-
lowest specific impulse in comparison to other
oxid
izers
.

-

critical

temperature

36,42
0
C

2013 SpaceForest Ltd.


All rights reserved.

Our

choice

Paraffin wax as fuel


Ad
v
antages
:

-

inexpensive and available
,

-

non
-
toxic
,

-

environmentally compatible
,

-

high regression rate, possibility


to use
a
single hole grain
,

-

short combustion chamber


with
a
single port grain
,

-
reusable grain and easy to mix


with additives
.


Disadvantages:

-

engine excitation problems
,

-

low density
0,9
2

[
kg/dm
3
]
,

-

low mechanical strength
.
figure

made

by Paweł Surmacz

2013 SpaceForest Ltd.


All rights reserved.

Proof of concept

1.
Minimal construction material cost.

2.
Use of industry standard equipment.

3.
Easy to transport test platform.

4.
Use of safe uninhabited area for testing.

2013 SpaceForest Ltd.


All rights reserved.

First cold test

3,2

[
kg
]

of N
2
O

in

8,0 [dm3]

45 [bar] tank
pressure

90 [mm2]
injector

throat


Liquid
:

2,54 [kg] & 0,82 [kg/dm3]

Vapour
:

0,66 [kg] & 0,13 [kg/dm3]


1,7 [s]

dicharge

time;
1,49 [kg/s]
flow

rate
; of N2O
liquid

phase


injector

discharge

coefficient

C
d
:





C
d

=
flow

rate

/
injector

throat

* (2 *
liquid

density

*
Δ
pressure
)^0,5


C
d

= 0,194


Valve gear box and hydraulic system
worked

properly
.

2013 SpaceForest Ltd.


All rights reserved.

First cold test

2013 SpaceForest Ltd.


All rights reserved.

First burn test

MDF tube saturated
with

paraffin wax










3,3 [s]

of
liquid

phase

burn

time as
expected

6
570

[
kNs
]

of total impulse


1797
[
Ns/kg
]

of specific impulse

large

excitation

of
thurst

on
the

end

of
liquid

phase


small

port
diameter

30 [mm] =>

large

oxidizer

mass
flux

1100 [kg/s*m2]

2013 SpaceForest Ltd.


All rights reserved.

First burn test

MDF tube saturated
with

paraffin wax

Grain

advantages
:

g
ood

density
1,02
[
g/cm
3
]


Grain disadvantages:

-

low

strength

-
>

grain damage
s

(several cracks),







-

small content of paraffin wax in the grain (36 % only),

-

low regression rate

(@ L/D = 15,4)

-

too big Oxidizer
-
to
-
Fuel ratio (O/F) =
8,6



N
2
O share
89,7%
,

-

graphite nozzle throat erosion,

2013 SpaceForest Ltd.


All rights reserved.

Test no.2 and no.3

Wastepaper tube saturated
with

paraffin wax


Different tank pressure

40 [bar]
and

57 [bar]


Other conditions unchanged


No
influence on
O/F
ratio



Visible

influence on efficiency


40 [bar]
-

1567 [Ns/kg]

57 [bar]
-

1719 [Ns/kg] (10% more than @ 40 [bar])


Big

influence on average thrust in the liquid phase

40 [bar]


1400 [N]

57 [bar]


2600 [N]


(86% more than @ 40 [bar])

2013 SpaceForest Ltd.


All rights reserved.

Test no.2 and no.3

Wastepaper tube saturated
with

paraffin wax


Stable

combustion
:
Ox

Mass
Flux

410


550
[kg/s*m2]


Grain

a
dvantages
:

-

good grain density:
1,01
[
g/cm
3
]
,

-

good ignition and test performance
,

-

good strength of
the

fuel grain
.


Grain

d
isadvantages
:

-

low paraffin saturation level

-

35% only
,

-

low availability of a thick
-
wall
ed

paper pipe
,


-

low regression rate
,

-

glue content (polyvinyl acetate + polyvinyl alcohol + kaolin)
,

-

empty spaces in spirally wound tubes


gas channels
,

-

graphite erosion
.

2013 SpaceForest Ltd.


All rights reserved.

Test no.5

Clean cellulose roll saturated
with

paraffin wax

-

no data, acquisition failure


-

impressive flame


-

too high regression rate


-

very

low O/F = 3,8


N
2
O share 79

%


-

risk of
setting

the

launch site


on
fire

by scraps of cellulose


-

lower grain density than MDF and wastepaper tube


0,86

[
g/cm
3
]
only


-

saturation problem, air bubbles in the grain

2013 SpaceForest Ltd.


All rights reserved.

2013 SpaceForest Ltd.


All rights reserved.

Test no.6


Polypropylene fiber roll saturated
with

paraffin wax


-

severed and burned injector

plate

-

low Throat/Injector ratio T/I = 4,0

-

high liquid phase average


thrust L
t

=
3300
[
N
]



Grain

advantages
:

-

only 30% of the PP reinforcement

-

easy to
saturat
e

-

fuel grain

unbreakable

-

regular

port surface after burning

-

no
risk

of throwing
burning

PP
pieces


Grain

disadvantages
:

-

to
o

low O/F = 3,8 ; N
2
O share
78 %
,


similar to cellulose fiber

2013 SpaceForest Ltd.


All rights reserved.

Test no.7 and no.8

Polypropylene fiber roll saturated
with

paraffin wax


Repeatability
verification

of test
results

with

the
same
test
bed and engine


similar test conditions:


Tank pressure 50


51
[
bar
]


similar

test
result
:


efficiency difference
1%
only


liquid phase average thrust

difference
3%
only


2013 SpaceForest Ltd.


All rights reserved.

Test no.9 and no.10

Polypropylene fiber roll saturated
with

paraffin wax


Cold test
s

due to ignition failure
s


Tank pressure
51

[
bar
]

and
52

[
bar
]

Combustion chamber (CC) pressure
4

-

5

[
bar
]

only

Liquid phase thrust
380

[
N
]

only


In
comparison
, h
ot

tests
in

the

same c
onditions
:


CC pressure
35



36

[
bar
]

Liquid phase thrust
3300

[
N
]


Both parameters about
8x bigger

t
han

@
cold test

2013 SpaceForest Ltd.


All rights reserved.

Test no.11 and no.12

Polypropylene fiber roll saturated
with

paraffin wax


C
omparison

of
the

T/I ratio
’s

influence
on
test
performance


Test no. 11

new injector 21x2,5 mm

T/I =
6,2

tank pressure 51 [bar]

CC pressure 35 [bar]

typical

Isp

=

1744

[Ns/kg]

ideal shape
of thrust characteristic
s


Test no. 12
injector
extended

to 21x2,8

T/I =
4,9

tank pressure 52 [bar]

CC pressure 38 [bar]

lower
Isp

=

1666

[Ns/kg]

visible excitation
of thrust


2013 SpaceForest Ltd.


All rights reserved.

Test no.12 and no.13

Polypropylene fiber roll saturated
with

paraffin wax

C
omparison

of
the

L/D
ratio

influence
on test performance


Test no. 12

port diameter
50

[mm]
;
L/D = 8,6

tank pressure 52 [bar]

efficiency 1666 [Ns/kg]

Ox

mass
flux

=

830 [kg/s*m2]

excitation
s

but
stable

flame


Test no. 13

port diameter
38

[mm]
;
L/D = 15,4

tank pressure 50 [bar]

efficiency 1637 [Ns/kg]

Ox

mass
flux

=

1650 [kg/s*m2]

e
xcitation
s but
extinguished flame

on

the

end

of
liquide

phase

2013 SpaceForest Ltd.


All rights reserved.

Test

no.13

2013 SpaceForest Ltd.


All rights reserved.

Test no.14

Polypropylene fiber roll saturated
with

paraffin wax


Check of
the

influence
of a
low T/I value on test performance


Test no. 14


injector
extended

to 21x3,0 mm

T/I =
4,3

port diameter 50 [mm]

tank pressure 52 [bar]

CC pressure
42

[bar]

efficiency 1708 [Ns/kg]


large excitation
of thrust

i
n
whole

liquid phase


2013 SpaceForest Ltd.


All rights reserved.

Test no.15 and no. 16

Polypropylene fiber roll saturated
with

paraffin wax

Test of
a
new injector type


Test no. 15
new injector
36x1,5 mm

T/I =
10,0

port diameter 50 [mm]

tank pressure 50,5 [bar]

CC pressure
42

[bar]

very low
Isp
. 1279

and [Ns/kg]


Test no. 16
injector
51x1,5 mm

T/I =
7,1

port diameter 38 [mm]

tank pressure 51 [bar]

CC pressure
38

[bar]

very low
Isp
.

1394

[Ns/kg]


very large excitation
of thrust

2013 SpaceForest Ltd.


All rights reserved.

Test no.17

Polypropylene fiber roll saturated
with

paraffin wax

Test bed change
s
: stable

trolley,
loose

engine
,





joint
ball on S
-
cell


modified injector

from

test 14


15 x 3,0 mm

T/I =
6,0

port diameter 50 [mm]

tank pressure 56 [bar]

goo
d

Isp

1812 [Ns/kg]


100 Hz
large excitation
of

thrust not eliminate
d


What to do ???


2013 SpaceForest Ltd.


All rights reserved.

Test no.18

Paraffin wax + PE wax + EVA


Test of
a
paraffin grain without reinforcement , with additives


the same injector
as
in

the

previous

test
,

pre
-
combustion chamber
used

for
the

first

time (
20% shorter grain
),

still to
o

low O
/F

ratio = 3,86


typical
Isp

= 1734 [Ns/kg]
,

good grain state after burn
,


excitation eliminated


100Hz

character of


fluctuation

but on
an

acceptable level


2013 SpaceForest Ltd.


All rights reserved.

Test no.19

Paraffin wax + PE wax + EVA


Using post
-
combustion
chamber

mixing plates


two mixing plate
s
added

into the post
-
cc

the same injector
and
pre
-
cc

10% shorter grain

ideal O/F ratio
=
5,6

(85% N
2
O)

flame

with

a
visible

standing
wave



first mixing plate damaged


no excitation
!

n
o tones into characteristic spectrum

(n
oise

character of thrust fluctuation
)

2013 SpaceForest Ltd.


All rights reserved.

Test no.20

Paraffin wax + PE wax + EVA

SpaceForest’s

invention to stabilize combustion and to eliminate
excitations: geometric configuration of the injector in a
conical shape.


new cone
-
shaped injector

modified first mixing plate (bigger ablative thickness)

the same pre
-
combustion chamber

similar grain without reinforcement


grain damaged due to defect of the cast

too low O/F ratio = 3,11 (76% N
2
O)


very good thrust characteristics

despite the big paraffin consumption






2013 SpaceForest Ltd.


All rights reserved.

Know
-
How

conclusions

N
2
O tank pressure
has the main influence on average thrust and on
resulting specific impulse
.

N
2
O

flow

rate

has

no influence on
O/F
ratio
.


T/I ratio reduction
i
ncrease

CC pressure and thrust

(
the

same T)
.


The most useful type of
reinforcement

was polypropylene fiber.



~
3
0
% share of PP does not attenuate the paraffin regression rate.


Enhancement

of the paraffin wax grain
with

various
additives

gave
good results, for example for hardness with
PE

wax
and for
flexibility with
EVA

-

ethylene copolymer and vinyl acetate.


Used

PP
fiber

and

additives do not prevent motor excitation.


The main cause
s

of the thrust excitation is a too big fuel share due to
the high regression rate of the paraffin wax
.

2013 SpaceForest Ltd.


All rights reserved.

Know
-
How

conclusions

Other
causes

of excitation during the test campaign:


-

i
njector

construction
based

on

vertically and
axially

located holes,

-

to
o

low T/I ratio,

-

too

large

Oxidizer

Mass
Flux
,

-

to
o

large

fuel

share
,

-

lack

of

pre
-
combustion chamber
.


W
ay
s

to eliminate excitation are:


-

injector
with

holes located away from the motor axis,

-

injector geometry based o
n

cone shape
as

proposed by
SpaceForest
,

-

proper

nozzle

throat

diameter

ensuring

T/I ratio

above

6,

-

proper

port
diameter

ensuring

Ox

Mass
Flux

below

1000 [kg/s*m2]

-

proper L/D ratio ensuring 85% share of N
2
O,

-

u
s
ing

a

pre
-
combustion chamber,

-

using mixing plates inside the post
-
combustion chamber.

2013 SpaceForest Ltd.


All rights reserved.

Flight experiment

Adaptation of
the

test engine to
a
rocket model

RTP7

the same engine (like in test 20) with added fins

aluminum tank filled with 3 [kg] of N
2
O

rocket height 3,3 [m]
,

start mass 18 [kg]

Flight

organized

and
supported

by
PTR


Polish

Rocketry

Society


Engine damage due to poor sealing near injector.

2013 SpaceForest Ltd.


All rights reserved.

Flight

experiment

Registered data of the engine thrust during the flight





two onboard
ARECORDER


f
light computers


a
cquisition

frequency 100 Hz






0,3 [s]

of start thrust on expected level ~
2
,
5

k
N

good start acceleration >10g


2013 SpaceForest Ltd.


All rights reserved.

Flight

experiment

2

Launch

experiment

by
Cracov

Team of PTR












K1X

rocket

tested

in

several

flights
,
equipped

first

time
with

hybrid

engine

based

on
N2O & PE
,

undependent

own

technology,


ideal

ignition
,
impressive

launch

performance,

2013 SpaceForest Ltd.


All rights reserved.

2013 SpaceForest Ltd.


All rights reserved.

Flight

experiment

2

Launch

experiment

by
Cracov

Team of PTR














t
hrust

based

on
flight

acceleration

data
-

above

1 [
kN
]


possible

flight

altitude

of 11 km
with

fully

filled

tank

SpaceForest

Ltd.

Pomeranian

Science & Technology Park


Al.Zwyciestwa

96/98

81
-
451 Gdynia


Poland


www.spaceforest.pl
,
www.ppnt.pl


spaceforest@spaceforest.pl
;



phone
:
+48
58 698 21 86 ;



fax
:
+48 58
698 21 88;



R&D

Department:


robert.magiera@spaceforest.pl
;

mob
: +48
608 666 164;




Contacts

2013 SpaceForest Ltd.


All rights reserved.

Thank

you

for
your

att
e
ntion

2013
SpaceForest

Ltd.


All
rights

reserved
.