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-   -   *Steam* model rockets! (http://www.oldrocketforum.com/showthread.php?t=11608)

blackshire 09-15-2012 11:06 PM

*Steam* model rockets!
 
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Hello All,

I came across a description (with a photograph--please see the two attached scans below) of a steam-powered model rocket that was developed in the late 1950s by Admiral Robert C. Truax, who is known for his steam rocket motor that powered Evel Knievel's Skycycle. It is on pages 684 and 685 of the NASA Reference Publication 1028 ("A New Dimension--Wallops Island Flight Test Range: The First Fifteen Years" by Joseph Adams Shortal), which was published in December 1978. The text is as follows:


TRUAX STEAM ROCKET

Admiral R. C. Truax of the Office of Naval Research had been involved with rocket engine development since the late 1930's. As a sideline interest, he invented a steam rocket as a possible answer to the need for an inexpensive and safe rocket for amateur and student scientists. The rocket was 6 feet 8 inches long and weighed 47.5 pounds with 30 pounds of water as the propellant. A propane gas burner was used to heat the water to a high temperature and pressure prior to launch. It exhausted from the rocket nozzle as steam. Truax had interested Experiment, Inc., of Richmond, Virginia, in developing the rocket, which they then offered for sale for $225, plus $275 for a launcher. A parachute recovery system for the payload was provided (ref. 75).

In January 1959, ONR asked NASA for permission to launch some of the Truax rockets at Wallops Island to verify their calculated performance. ONR was interested in the rockets for use in cloud seeding for weather modification at altitudes up to 30,000 feet. The calculated altitude achievable by the steam rocket was stated to be between 50,000 and 75,000 feet.

Krieger [Dr. Robert L. Krieger, the Director of the Wallops Island Facility] was interested in this unique rocket approach for amateurs and recommended that the requested assistance be provided. He assigned a PARD [Pilotless Aircraft Research Directorate, the old Wallops organization name under the NACA (National Advisory Committee for Aeronautics)] designation of B20 to the vehicles because of their developmental nature. Figure 462 [see the attached scans below] shows two of the three rockets prepared for launching on February 25, 1959. Under the direction of Admiral Truax, launch operations were carried out by representatives of Experiment, Inc., and ONR, with Wallops' assistance. The first rocket, launched at 1:48 p.m., left the launcher smoothly and appeared to be stable during and after powered flight. The performance, however, was disappointing. Tha altitude reached was only 5,000 feet, and the nose cone failed to open as planned, to deploy chaff. In the second attempt, the safety valve on the rocket opened during the heating cycle, and no launch was made. In the third attempt, at 4:04 p.m., the altitude reached was only 2,000 feet, and considerable wobble was noted in the flight. The parachute did not deploy (ref 76). Despite this less-than-expected level of performance, the tests did demonstrate that steam could be used as a rocket propellant. [This performance would be fine for model rocket purposes. References 75 and 76 are below, and below them are the attached scans.]

75. The Truax Steam Rocket, Model TR-1, A High Performance Rocket Designed Specifically for the Serious Amateur and Student Scientist. Experiment Incorporated, Richmond, Va.

76. Wallops PARD Log, Feb. 25, 1959.

Brain 09-16-2012 09:49 AM

Fascinating!
I would think that this method would fall under the HPR category... 30 lbs. of water fuel? How many ft. per second did it say? Nice...!

blackshire 09-16-2012 10:45 PM

Quote:
Originally Posted by Brain
Fascinating!
I would think that this method would fall under the HPR category... 30 lbs. of water fuel? How many ft. per second did it say? Nice...!
Considering its relatively low ISP, the Truax TR-1 steam rocket might have been in the category of what today would be called LPRs (Large Model Rockets), in the "borderlands" between model rockets and HPRs. With today's engineering, I think steam-powered model rockets of the size of the Vashon/Estes Cold Propellant model rockets are feasible; like Truax's steam rockets, they could have calibrated-pressure safety valves (like those in pressure cookers) to prevent steam explosions if the water in the rockets was over-heated.

Bill 09-16-2012 11:50 PM

Quote:
Originally Posted by blackshire
Considering its relatively low ISP, the Truax TR-1 steam rocket might have been in the category of what today would be called LPRs (Large Model Rockets), in the "borderlands" between model rockets and HPRs. With today's engineering, I think steam-powered model rockets of the size of the Vashon/Estes Cold Propellant model rockets are feasible; like Truax's steam rockets, they could have calibrated-pressure safety valves (like those in pressure cookers) to prevent steam explosions if the water in the rockets was over-heated.



Other than being able to fly them during a burn ban, I would think the complexity, the length of time needed to liftoff once on the pad and that fact that more than 15 or 30 feet separation is required would turn many people off. Just saying...


Bill

blackshire 09-17-2012 12:21 AM

Quote:
Originally Posted by Bill
Other than being able to fly them during a burn ban, I would think the complexity, the length of time needed to liftoff once on the pad and that fact that more than 15 or 30 feet separation is required would turn many people off. Just saying...
With a safety valve in the rocket (the Vashon/Estes Cold Propellant rockets also had such valves), the same 15' - 30' separation could be used. Regarding the "water heating wait," small Vashon/Estes-size steam rockets would hold much less water than the 6' 8" long Truax TR-1 educational steam rockets (which were intended to reach the stratosphere), so a propane burner of reasonable size should be able to heat the water fairly quickly.

Bill 09-17-2012 12:36 AM

Quote:
Originally Posted by blackshire
With a safety valve in the rocket (the Vashon/Estes Cold Propellant rockets also had such valves), the same 15' - 30' separation could be used.



How long and how dangerous would that plume be should the valve open?

Also, we need some way to disarm and safe the rocket once heating has begun.


Bill

blackshire 09-17-2012 01:34 AM

Quote:
Originally Posted by Bill
How long and how dangerous would that plume be should the valve open?
That depends on the size of the steam rocket motor--my preferred size is 1" in diameter and 6" - 8" long. Having created jets of steam from comparable volumes of water (in small laboratory flasks with rubber stoppers and glass tubes), I don't think anyone farther away than ~4 feet would be in danger of getting scalded. The actual steam (which is invisible) condenses into white water vapor (tiny droplets of *liquid* water, an aerosol) within inches of the vent tube, and the water vapor quickly diffuses and cools.
Quote:
Originally Posted by Bill
Also, we need some way to disarm and safe the rocket once heating has begun.
Shutting off the burner (or electric water heater) would be one way to do this. Also, since the rocket's recovery system could use the same "controlled slow leak" auxiliary pressure tank & timer disc system as the Vashon/Estes Cold Propellant rockets (the timer discs in the steam rocket could be made of fiber or finely-perforated metal instead of paper as in the Vashon/Estes models), the auxiliary pressure tank could also be equipped with a pressure relief valve; this valve could be manually (but remotely) opened using a camera remote shutter release cable or something like it.

Brain 09-17-2012 03:59 PM

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Are there schematics for a basic design for this sort of rocket somewhere?
What kind of expertise does one need to put together a system like this?
I think a Victorian-era-style model rocket would be the perfect vehicle (pardon the pun) for this type of propulsion... someone could dive into a whole new sub-genre in model rocket design! Steampunk is huge...
Hmmmm... :rolleyes:

Brain 09-17-2012 04:08 PM

'Steam Trek'?
 
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BTW: Just for gits and shiggles, I thought I'd show you a recent steampunk-based bit of 3D/digital artwork I did a while back... ever see the video 'Steam Trek'? :chuckle:

blackshire 09-18-2012 02:48 AM

Quote:
Originally Posted by Brain
Are there schematics for a basic design for this sort of rocket somewhere?
What kind of expertise does one need to put together a system like this?
I think a Victorian-era-style model rocket would be the perfect vehicle (pardon the pun) for this type of propulsion... someone could dive into a whole new sub-genre in model rocket design! Steampunk is huge...
Hmmmm... :rolleyes:
I have only very recently heard of the Steampunk genre (modern devices that use Victorian Age technology). This Google page (see: http://www.google.com/search?sclien...K=Google+Search ) lists a book and a web site devoted to steam rocket design, and has numerous images of various steam rockets.


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