Search found 12 matches

by VicHanby
Fri Oct 24, 2014 10:40 am
Forum: Valveless pulsejet forum
Topic: Questions about CFD analysis and What is Uflow1D?
Replies: 3
Views: 2295

Re: Questions about CFD analysis and What is Uflow1D?

[quote="sid_raptor"]So i have been doing a lot of reading about the black magic that actually goes on inside a valveless. I was thinking, i would like to do a CFD analysis of a valveless engine. The problem is im not very good at doing a CFD About 18 years ago we built a CFD model of a (valved) Schm...
by VicHanby
Fri Oct 24, 2014 10:20 am
Forum: Valveless pulsejet forum
Topic: Jam jar jet fuel system
Replies: 8
Views: 3715

Re: Jam jar jet fuel system

I don't know anything about one way valves. Anything with a fast response (how many hertz does a jam jar max out at?) I've attached a pdf of the pressure trace from a Reynst pot taken from a paper published in 1967. The major time divisions in pic (a) are 0.1 sec so it's frequency is ~ 58Hz. This i...
by VicHanby
Mon Jul 19, 2010 11:54 am
Forum: Valveless pulsejet forum
Topic: metal jam jar experiments
Replies: 458
Views: 181427

Re: metal jam jar experiments

This is one I built to look at alternate fuels to methanol - didn't think the rice pudding tins were strong enough. It's just a length of 3" pipe and some flanges. The health and safety police at the university stopped me working on it but it runs for quite some time if you put it in a bucket of wat...
by VicHanby
Mon Jul 12, 2010 5:01 pm
Forum: Valveless pulsejet forum
Topic: Energy distribution in a Pulse jet.
Replies: 22
Views: 6812

Re: Energy distribution in a Pulse jet.

Hi Mark,

Sorry about the long delay. I've a strong suspicion that Thring's son is a Prof. at Loughborough University (where I used to work). I'll chase this up.

Regards

Vic
by VicHanby
Fri Jan 08, 2010 11:53 am
Forum: Valveless pulsejet forum
Topic: Energy distribution in a Pulse jet.
Replies: 22
Views: 6812

Re: Energy distribution in a Pulse jet.

Hi Mark, I arrived at Sheffield University in 1963 to start a PhD programme on a topic I hadn't heard of - pulsating combustion. Thring had worked on coal combustion and was interested in a chapter in Reynst's book by a guy called Sommers, who had successfully built a rig which burned brown coal. Th...
by VicHanby
Mon Jan 04, 2010 7:32 pm
Forum: Valveless pulsejet forum
Topic: Energy distribution in a Pulse jet.
Replies: 22
Views: 6812

Re: Energy distribution in a Pulse jet.

Hi Fedde, I think there's a bit of confusion as to the Reynst pot. If you read his papers in the Thring book, what I would regard as the 'real' pot is the vessel (jam jar, w.h.y.) with a hole in it. This operates at a very low frequency which is so far removed from any resonant mode that an acoustic...
by VicHanby
Mon Jan 04, 2010 6:49 pm
Forum: Valveless pulsejet forum
Topic: Energy distribution in a Pulse jet.
Replies: 22
Views: 6812

Re: Energy distribution in a Pulse jet.

Hi Mike I came across pulse combustion in 1963 when I started a PhD at Sheffield University trying to get a Schmidt tube device to burn pulverised coal. There was a paper in Reynst's book which suggested a guy called Sommers had achieved this using brown coal. The UK National Coal Board had tried to...
by VicHanby
Mon Dec 21, 2009 10:00 am
Forum: Valveless pulsejet forum
Topic: Energy distribution in a Pulse jet.
Replies: 22
Views: 6812

Re: Energy distribution in a Pulse jet.

I think this depends a lot on the engine configuration. I used to do a demo in my combustion lectures using my favourite Reynst pot - a 3" dia 6" long can (actually an empty cream rice pudding tin) with a 1/2" hole in the lid and methanol fuel. By weighing this before, during and after a 'run' (abou...
by VicHanby
Mon Jul 02, 2007 9:58 am
Forum: Valveless pulsejet forum
Topic: Reynst time again...
Replies: 38
Views: 14246

Andrew: It was a model of a bench-top gas-fired tube we had in the lab, so we could measure amplitude, frequency etc. Basically it was a variable length 2" tube with a 1" air inlet and a 3/8" propane injector. It had a flap vale attached whch we modelled as a low resistance with a negative pressure ...
by VicHanby
Fri Jun 29, 2007 10:36 am
Forum: Valveless pulsejet forum
Topic: Reynst time again...
Replies: 38
Views: 14246

Haven't visited the forum for a while but the CFD models of the Pot are a great development. Maybe I've missed something but what software are you guys using for this? A good few years back we built a model of a Schmidt tube (including combustion) using CFX4, but couldn't get any funding to carry on...
by VicHanby
Tue Aug 08, 2006 8:52 am
Forum: Valveless pulsejet forum
Topic: New Pot on the Block
Replies: 47
Views: 17550

re: New Pot on the Block

The efficiency depends on which calorific value you use. Based on the gross CV the efficiency appears to be 91%, if you use the net CV (no condensation of water vapour) it's 104%. This suggests that water would be accumulating in the bottom of the pot (unlikely?). Of course, these measurements are d...
by VicHanby
Tue Aug 01, 2006 3:17 pm
Forum: Valveless pulsejet forum
Topic: Reynst
Replies: 16
Views: 9124

re: Reynst and the Black Book

Re the Black Book - I did my PhD at Sheffield 1963-6 and Dennis Brown was my supervisor. I built a valved pulse combustor which burned 50 lb/hr pulverised coal and it was all very exciting. I'd really like to find a resonably-priced copy of Reynst's book, I've only got photocopied bits of it. The co...