Hercules Engines

"Tarver Engineering" wrote in message
...

"Jim Knoyle" wrote in message
...

"Tarver Engineering" wrote in message
...

"Jim Knoyle" wrote in message
...

Hey, Splaps. Next time you are ever near a DADC or it's diagram,
check out what they have at the other end of the tubing connected
to the fitting labeled *TOTAL*. Only ONE pitot tube!

Yep, the term Total means they added two sensors.

Nope, the pitot tube detects static pressure + impact pressure.
Read the book(s).

I have been writing that to you for years, Knoyle. That is why you seem
such an idiot when you insist a pitot port is a pitot tube.

Total means there is more than one sensor, nothing more.

You really don't understand how that one little opening on the end
of that pointy thing up front can detect static pressure (altitude)
as well as impact pressure (airspeed), do you. That's sad!

Rick wrote:
You must be a common troll, Tarver, it is inconceivable that an adult
with your level of reading and reasoning skills could function outside a
constant care facility. Maybe you don't.

Oh no, give Splappy his due. He's far from a common troll. He actually
believes the bull**** he posts!

------------------------------------------------------------------------
|Rich Ahrens | Homepage: http://www.visi.com/~rma/ |
|-----------------------------------------------|
|"In a world full of people only some want to fly - isn't that crazy?" |
------------------------------------------------------------------------

From: Rick
Date: 1/17/2004 1:45 PM Central Standard Time
Message-id: . net

B2431 wrote:

If you mount them in series you get plus -- minus -- plus-- minus etc.
This
will introduce one heck of an error if it works at all.

They will produce voltage and current, but like you wrote,
series connecting them will introduce errors which make them
unsuitable for instrumentation or measurement use because of
the higher current flow through each junction.

Rick


True, you get a thermopile which has nothing to do with instrumentation.

Dan, U. S. Air Force, retired

From: "Tarver Engineering"
Date: 1/17/2004 1:49 PM Central Standard Time
Message-id:


"Rick" wrote in message
news
B2431 wrote:

If you mount them in series you get plus -- minus -- plus-- minus
etc. This
will introduce one heck of an error if it works at all.

They will produce voltage and current, but like you wrote,
series connecting them will introduce errors which make them
unsuitable for instrumentation or measurement use because of
the higher current flow through each junction.

No, but parallel is better, although any way you look at it the sensor
system produces a Total.

So every T.O. I ever read on the subject and every TIT indicator labelled
"turbine inlet temperature indicator" I ever changed or calibrated were wrong?

Dan, U.S. Air Force, retired

From: "Tarver Engineering"


"B2431" wrote in message
...
If you ever get a chance to look at a jet engine look at the EGT ring of
thermocouples. You will see they are in parallel.

But T8 is not TIT and it is fed to a totalizer, as deviding only reduces
reliability.


You claim to have been a jet mech. If this were actually true you would know
the EGT thermocouple ring is easier to see than TIT. The front end of a jet
engine has more stuff in the way.

Dan, U.S. Air Force, retired

From: "Jim Knoyle"
Date: 1/17/2004 3:48 PM Central Standard Time
Message-id:


"Tarver Engineering" wrote in message
...

"Jim Knoyle" wrote in message
...

"Tarver Engineering" wrote in message
...

"Jim Knoyle" wrote in message
...

Hey, Splaps. Next time you are ever near a DADC or it's diagram,
check out what they have at the other end of the tubing connected
to the fitting labeled *TOTAL*. Only ONE pitot tube!

Yep, the term Total means they added two sensors.

Nope, the pitot tube detects static pressure + impact pressure.
Read the book(s).

I have been writing that to you for years, Knoyle. That is why you seem
such an idiot when you insist a pitot port is a pitot tube.

Total means there is more than one sensor, nothing more.

You really don't understand how that one little opening on the end
of that pointy thing up front can detect static pressure (altitude)
as well as impact pressure (airspeed), do you. That's sad!


The hole on the front only detects pitot pressure. If there are holes on the
side are for detecting static pressure.

Dan, U.S. Air Force, retired

"B2431" wrote in message
...
From: "Jim Knoyle"
Date: 1/17/2004 3:48 PM Central Standard Time
Message-id:


"Tarver Engineering" wrote in message
...

"Jim Knoyle" wrote in message
...

"Tarver Engineering" wrote in message
...

"Jim Knoyle" wrote in message
...

Hey, Splaps. Next time you are ever near a DADC or it's diagram,
check out what they have at the other end of the tubing connected
to the fitting labeled *TOTAL*. Only ONE pitot tube!

Yep, the term Total means they added two sensors.

Nope, the pitot tube detects static pressure + impact pressure.
Read the book(s).

I have been writing that to you for years, Knoyle. That is why you
seem
such an idiot when you insist a pitot port is a pitot tube.

Total means there is more than one sensor, nothing more.

You really don't understand how that one little opening on the end
of that pointy thing up front can detect static pressure (altitude)
as well as impact pressure (airspeed), do you. That's sad!


The hole on the front only detects pitot pressure. If there are holes on
the
side are for detecting static pressure.


No, sorry Dan, you'll have to refer to a more modern air data computer.
When the label at the top of the ADC switched from pitot to total, the
definition for Total Pressure (Pt) was given as:
"This is a pressure input (from the aircraft pitot probe) which varies
both with altitude and aircraft speed. (Range 3.11 to 42.50 in. Hg.)"
*This was a direct quote from a Honeywell HG280D DADC guide*
The book goes on to explain how the delta Ps is removed to arrive at
a more accurate airspeed. The Ps, whether obtained from the static
port(s) on the probe or flush mounted ports on the fuselage, is fed
through another fitting on the DADC (labeled static) and is something
else entirely. It does factor in to the math.

JK

"Steve R." wrote in message
...

"Ralph Nesbitt" wrote in message
y.com...

Lockheed has used some version/model of the Allison T-56 since "1956" on
all
C-130 models. Yes it is called a Allison T-56 because it was a "56
model
Allison Turbine Engine". The same year the C-130 first flew at/from
Marietta, Ga.

There have been numerous improvements made to this basic engine design
over
the years to incorporate new technology, increase power, etc., but the
basic
design remains the same.

The "T 56-15 Model Allison Engine" referred to by Phil, means a Allison
T-56
engine incorporating the 15 th update.

Check the model # of the Allison T-56 engine used on the C-130J. If you
do
a
little checking, you will find the T-56-15 engine was used on late C130
E
&
G models.

Tarver you claim to be an "Electrical Engineer". Don't you know better
than
to argue with a person quoting the manual on a given/specified item?
Apparently not.
Ralph Nesbitt
Professional FD/CFR/ARFF Type


Actually, the J has the AE2100D3 engine. The T56 production line was shut
down shortly after the J went into production.
Steve R.

You are correct. The AE2100D3 engine looks similar to the T-56 series,
unless you see them size by side on an engine stand sans prop. The AE2100D3
makes the T-56 engine look like a "Baby" size wise. Thanks for helping
Tarver out. I was waiting for his reaction.
Ralph Nesbitt
Professional FD/CFR/ARFF Type

(B2431) wrote in
:

From: Jim Yanik
Date: 1/17/2004 10:17 AM Central Standard Time
Message-id:

(B2431) wrote in
:

From: Jim Yanik
Date: 1/16/2004 6:53 PM Central Standard Time
Message-id:

"John R Weiss" wrote in
news:Sp%Nb.73504$nt4.98595@attbi_s51:

"Phil Miller" wrote...

Yes really, on every jet engine TIT is Total Inlet Temperature.

Yep.

I ask because I came across an interesting paragraph in the
T56-A-15 service manual yesterday. Went like this...

...measures the turbine inlet temperature by means of
thermocouples...Eighteen thermocouple assemblies are mounted in
the turbine inlet casing of each engine...One thermocouple of
each assembly is connected to the turbine inlet temperature
indicating system, and...one...is connected to the electronic
datum control system. The 18 indicating system thermocouples are
connected in parallel [!!] by the indicator turbine thermocouple
harness assembly,

I'm surprised you ever doubted the truth on this one!


So, let's revise.

That's going a bit too far... Nobody can revise the Tarver
Chronicles! :-)


bimetallic thermocouples generate millivolt signals,and paralleling
them would not work.Standard practice is to series-connect them,and
compare to a reference junction.Do these assemblies include signal
processing to convert the mV signal to a digital form,which could
then be sent on a parallel bus?

--
Jim Yanik
jyanik-at-kua.net

On every aircraft I ever worked on thermocouples were in parallel if
there were two or more.

Dan, U.S. Air Force, retired


Well,I guess they aren't bimetallic thermocouples,then.
Anyone have any speculation on what sort of signal will work with a
parallel connection?

--
Jim Yanik
jyanik-at-kua.net


All thermocouples are bi-metallic.

OK, try this on for size. Jet engines use chromal-alumal (type K) and
recips use iron-constantan (type J) thermocouples.

The different bi-metal combos generate different volts/degree.

The wires are also
made of the same type of material. If you mount several thermocouples
in parallel then all plus wires match and all minus wires match. As
far as the cold junction end is conserned the hot end has one
thermocouple.

If you mount them in series you get plus -- minus -- plus-- minus
etc. This will introduce one heck of an error if it works at all.

Just connecting them to a copper wire bus makes another bi-metal
junction,too,although it's not in the area being measured,and thus more
stable.


If you ever get a chance to look at a jet engine look at the EGT ring
of thermocouples. You will see they are in parallel.

Dan, U. S. Air Force, retired

You wire thermocouples in series and the voltage outputs add
together(sum).Parallel them,and one voltage bucks against the other.
Paralleling thermocouples is like parallelling two batteries of different
voltages.One works against the other.

I worked on thermocouple calibration while in the USAF,as a PMEL
technician(Precision Measurement Electronics Laboratory).


--
Jim Yanik
jyanik-at-kua.net

From: Jim Yanik


snip

bimetallic thermocouples generate millivolt signals,and paralleling
them would not work.Standard practice is to series-connect them,and
compare to a reference junction.Do these assemblies include signal
processing to convert the mV signal to a digital form,which could
then be sent on a parallel bus?

--
Jim Yanik
jyanik-at-kua.net

On every aircraft I ever worked on thermocouples were in parallel if
there were two or more.

Dan, U.S. Air Force, retired


Well,I guess they aren't bimetallic thermocouples,then.
Anyone have any speculation on what sort of signal will work with a
parallel connection?

--
Jim Yanik
jyanik-at-kua.net


All thermocouples are bi-metallic.

OK, try this on for size. Jet engines use chromal-alumal (type K) and
recips use iron-constantan (type J) thermocouples.

The different bi-metal combos generate different volts/degree.

The different combinations are for different temperature ranges. As I said all
thermocouples are bi metallic. The metals are determined solely by the
temperature being measured.


The wires are also
made of the same type of material. If you mount several thermocouples
in parallel then all plus wires match and all minus wires match. As
far as the cold junction end is conserned the hot end has one
thermocouple.



Just connecting them to a copper wire bus makes another bi-metal
junction,too,although it's not in the area being measured,and thus more
stable.

The discussion is about aircraft. In aircraft the wires that run to the
indicator is of exactly the same type as in the thermocouple. The total wire
resistance is 8 ohms in ALL aircraft. There are a pair of wire spools in one
leg that are used to adjust this. Copper wire is never used.

If you ever get a chance to look at a jet engine look at the EGT ring
of thermocouples. You will see they are in parallel.

Dan, U. S. Air Force, retired

You wire thermocouples in series and the voltage outputs add
together(sum).Parallel them,and one voltage bucks against the other.
Paralleling thermocouples is like parallelling two batteries of different
voltages.One works against the other.

I worked on thermocouple calibration while in the USAF,as a PMEL
technician(Precision Measurement Electronics Laboratory).

--
Jim Yanik
jyanik-at-kua.net


PMEL calibrated the test equipment I used on aircraft such as the jet cal
tester I used to test thermocouple systems. I can see why you might use copper
wire since it is more flexible than the chromel-alumel or iron-constantan we
used on aircraft. I don't know if you had to silver solder the leads to the
pins of cannon plugs, but on aircraft they had to be.

Dan, U.S. Air Force, retired