CTI Pro150 Aerospike test

[Justy]

Behold! Cesaroni put an aerospike nozzle on a Pro150 casing. It is a thing of beauty. No longer do large projects need launch rails... just load the motor, pick the rocket up, and drop the spike into the ground!

There's a picture here, and cooler yet, there's a video of a test firing. I bet the igniter they used had more energy than the Pro38 I used for my L1 cert.

 

[edwardw]

On the topic of aerospikes...my friends and I have just solid modeled a KNO3/Sugar engine with an aerospike nozzle. And tomorrow we have time on the CNC machine making the part out of graphite. We thought we would give it a try. We don't know how well it will work but should be fun anyway.

 

[Ryan S.]

nice, do you have an pictures? I am interested in how it is attached and how it was mad etc. I am trying to get lots of info about aerospikes.

THanks

By the way that motor is awesome

 

[edwardw]

This is the way we decided to design it. First we designed an engine for a regular circular throat. Then we got the area of the throat. We then took two circles and made the area between the cirlces the area equal the area of the throat. To keep the area constant the ring part of the spike is angled at 30 degrees, and the spike is a 30,30,120 triangle. To get compression on the gasses we made the back part of the spike mirror the front end of the spike. We truncated the spike when the diameter was .5", then tapped and threaded it. We have a holly steel tube that is threaded that threads onto the spike. It also threads to the forward closure. By this the spike is held in. The circular ring is held in by regular snap ring system.

No pics as we haven't machined it yet.

Edward

 

[Ryan S.]

nice dude, please post some pics whe you finish it, I am very interested

 

[Loki]

I did my first aerospike test back in January.

It was a 76mm motor. The aerospike nozzle has a full annular port and is adjustable. Unfortunately, the graphite fractured on the first test firing, ejecting the pintle and causing the motor to chuff badly. I have made some design modifications and as soon as I find the time to machine new parts I'll fire it again.

 

[Johnnie]

The evolution of the Aerospike is progressing...Very nice work Jeff.


signed
New customer

 

[rstaff3]

Jeff, are you going to test this nozzle 'along side' standard nozzels with a baseline propellant? Several people have reported work on aerospikes for solid motors but I don't remember seeing any test results. Just curious if they will add performance or only have a 'cool factor'.

Hope to see a test firing at an MDRA launch in the spring or summer!

 

[Ryan S.]

I take it yours is held in with a rod to the forward closure like all the others I have seen.

What is the point of the forward closure? If only you still had it or pics of the indivicual parts to show

 

[edwardw]

The forward closure it the top closure of the motor - the closure on the opposite side of the nozzle.

 

[Loki]

That was the idea, to show a performance difference. I think it will be hard to show a significant advantage, because even in theory the advantage is not large and there is enough noise in our measurements to potentially hide the effect. Only more experiments will tell for sure. Still, it's worth doing just for the "cool factor".

The last test firing was at the Janurary MDRA launch. It's likely the next will be as well.

Originally posted by rstaff3
Jeff, are you going to test this nozzle 'along side' standard nozzels with a baseline propellant? Several people have reported work on aerospikes for solid motors but I don't remember seeing any test results. Just curious if they will add performance or only have a 'cool factor'.

Hope to see a test firing at an MDRA launch in the spring or summer!

 

[Loki]

I don't want to give away all my secrets until I have something working.

Originally posted by Ryan S.
I take it yours is held in with a rod to the forward closure like all the others I have seen.

What is the point of the forward closure? If only you still had it or pics of the indivicual parts to show

 

[rstaff3]

Originally posted by Loki
That was the idea, to show a performance difference. I think it will be hard to show a significant advantage, because even in theory the advantage is not large and there is enough noise in our measurements to potentially hide the effect. Only more experiments will tell for sure. Still, it's worth doing just for the "cool factor".

The last test firing was at the Janurary MDRA launch. It's likely the next will be as well.

I fully agree about the cool factor. And it's good to see people pushing our hobby forward. Hope the weather will be warmer at the end of the month.