MEng project: paddle blades with holes

Hello there,

Firstly, Merry Christmas to everyone - I hope you are all having an enjoyable one.

Secondly, for those of you who are interested, I thought I would put up a wee update on my paddle project. For those of you who don't know what it's about, a quick explanation. My idea is to put holes in paddle blades to encourage flow through the blade, to dissipate the horse shoe shaped vortex (the whirlpools you see when paddling are either end of this), because there is a lot of energy involved in creating this vortex. In short, my idea is to reduce the size of the vortex, therefore reducing the energy that has been consumed in creating that vortex. So although the force will be reduced from reducing the blade area, hopefully more will be gained from putting less energy into the water, so hopefully, the net effect will be a more efficient paddle. If it works, because of the effects on the strength, it think it is likely that the paddle will be most suitable for long distance touring.

Using computational fluid dynamics (CFD) analysis I can measure the turbulent kinetic energy in the water - a visual representation of my CFD analysis so far is shown below, illustrating turbulent viscosity for a paddle blade with no holes and 25mm holes respectively, in the vertical position.












As can be seen from the images, there is less turbulent viscosity occuring in the paddle blade with 25mm holes, therefore it can be concluded that less energy has been put into the water. Turbulent viscosity plots are likely to be good indication of turbulent kinetic energy. The turbulent kinetic energy is related to the amount of energy that has been put into the water.

A few thoughts:
- please understand that my project is not finished, and these are only preliminary results and I have not fully investigated the effects yet
- the CFD analysis only considers the blade in vertical position
- there are a number of other significant simplifications made for practical and time constraints
- holes may have significant effects on the entry and exit motion of the blade
- more in depth CFD analysis would give a better idea of the effects
- more work could be carried out on optimal hole size and configuration
- I am looking into patents, and will hopefully have it sorted early in the new year
- in the end, if this design works, I would like it to be accessible to everyone, so that they could take their cordless drill and modify their paddle to make it more efficient, however, regarding business, if anyone is going to make any money from it, I would like it to be me, hence why I am sorting out a patent

I would greatly appreciate your thoughts and advice on anything you think you can help with.

How high is yours?

I said I would put this in. Just a quick spreadsheet graph so you know how high a cliff is when you throw something off it and count how long it takes to get to the bottom. The formula used is: s = ut + 0.5at^2, where s height, u = initial velocity, a = acceleration = gravity = 9.8m/s^2, t = time.

NB This formula doesn't take account of friction which means that for all our purposes, the height maybe negligibly less than the graph shows.

29/30 Sept, 1 Oct 06

So here I am at the end of my adventure. On the train, that left at 4.10pm from Mallaig, that I thought left at 10.30am! (Mental note: pay more attention to the wee print in timetables.) We've just arrived in Fort William. I'll tell the last few days story in revers chronological order, as I think it's funnier that way for some reason.

Sunday morning, I arrived in Mallaig about 10am on the ferry from Aramadale. As you know, I arrived at the train station thinking my train was at 10.30am. To my dismay, after chatting to others who had made the same mistake, we realised the 10.30 train had stopped last week, and the next one was at 4.10pm. "So what do I do now?" I asked myself. I contemplated cycling to Arisaig to pass the time, but was tired already so I decided that sleeping was better than cycling. I bought a paper, set my tent up next to the car park, next to the train station, set alarm on my phone, (then the battery went flat!), then fell asleep. I was dozing, looked at watch around 3.30pm, got up and got on the train. I timed how long it took to unset my tent (North Face Tadpole 23): 5 minutes exactly - with this time, I was happy.

When I woke up on Sunday morning, I was comfortingly warm, and it was getting light. It was already lighter than it was when I set up camp, and I was looking forward to getting some better photos of my campsite, which I was very proud of. It was 7.30ish. I wanted to wait as long as I could before unsetting my tent so I had as much light as possible for the photos. So I packed up everything else that I could, and went for a walk along the shore. I found some nice pumis stones and shells, and worked on my stone skimming skills.

After unsetting my tent, I left the legacy of a carved stick with shavings at my campsite for the sake of something to do. Then I just sat with my warm tea (put in the flask and Gordons' last night), and took in the view. The natural beauty of the place was breath taking, and I was lost for thought as I sat in awe. Then the ferry arrived and I got on it - thankfully!

So last night, after passing my 4* sea kayak assessment, I was searching for a campsite. I wanted something on the Armadale side of the hill just outside Isleornsay, but wasn't finding much. I ended up cycling all the way to Armadale (or just before) , passing lots of places that would have been great campsites, if it wasn't for the houses built on them. On the opposite side of Armadale Castle (Clan Donald) there was a stone path leading down to the shore - I was sure that there was a campsite down there. And sure enough, after I skidded down the wee track, and walk along a bit, and up some stoney steps, I found a beautiful wee campsite, only big enough for a small tent. So I set up camp, and had what food I left for my dinner. I was surprised that I hadn't got food poisoning by this point, as I was still using the same food bag as the start of the trip, which included broken eggs. I only had one egg left, and was not prepared to boil water for one egg, so I took job in throwing it against the rocks. I actually dropped it off the cliff that my camp site was on, counted how long it took to drop (1.5 secs) and wondered how high it was. See my next blog - I have done a quick graph of time v. distance so you can work out how high cliffs are by counting when you drop something. It was 8pm, and I had just passed my 4* so was keen for a pint. I donned my jeans, and white trainers, picked up my head torch, had a quick squirt of Lynx, brushed my teeth, and set off in search of a pub. I didn't know if there was one, so I phoned a few people, to no avail. Armadale - nothing, apart from a house with Indian dance music playing outside, and someone dancing with a stick flaming at both ends in their hands (I think). I walked past quickly, half expecting to see an axe being hurled at me or something. However, I heard womens' voices, so I was also tempted to go and say hello. I saw more lights, half a mile down the road, so was more hopeful of a pub.

Right enough, I came to a place with people standing outside smoking - sure sign of a pub post-the new law banning smoking in pubs in Scotland. I asked the guy outside if this was pub, and he said "Aye" and took me along to the public bar (I would have walked into the lounge bar which would surely have had a higher percentage of non-locals!). To my surprise, I recognised the man. "Neil?" I said. "Aye" he said. "It's Tom." "Oh aye, John, how are ye?" "No, Tom, Dannys wee brother" It was Neil McPhee, from Tarscavaig, who worked with my big brother on fish farms, and was the piper at Dannys wedding. So, I got a warm welcome, and started drinking and chatting with him, his wife Jackie, his daughter Emma, and her boyfriend John-Murdo. The rest of the night was a mixture of laughs, lager, whisky, pool, and is another story in itself. But it ended with a lift home, so I was happy.


















So that's Saturdays campsite, and Thursdays campsite I have already written about in my previous blog, but what about Friday I hear you ask - well maybe not, but if you'd like to hear about it please read on. It was a mile North or so of Camascross. I found a wee track going down to a clearing on the shore. The main disaster this evening was a cog coming off the derailleur of my bike when I was cycling. I carried on rolling, pushing my bike along by foot, but my bike was not longer cycleable, so I was going to have to walk back later to find the cog and fix my bike, so I did. My main inspirational moment was eating a can of beans, cleaning the can, then using the can to cook pasta. My main uninspirational moment was the fact that my campsite was covered in sheep shit. Anyway, I went to bed, had a broken sleep because it was cold and my sleeping is feeling its old age, and woke up to one of the prettiest sunrises I have ever seen, and don't have any photos because I had lost my phone. It was found and handed in at the hotel in Isleornsay, thanks to the honesty of the people of Skye, and I collected at the end of the day.

The rest of the trips activities were of a sea kayaking nature, and are a more technical story which I will not go into. The only other thing I found enjoyable before getting home was chatting to a friendly guy called Bobby "Corson" - we chatted about various things including the surrounding highlands that we were travelling through. I am very pasionate about the Highlands, and would like to spend a lot more time in them.

OK, enough. Thank you for reading up to this point. If you have, then I'll take it as a complement in that I have manged to hold your attention for this long. I'm new to the blog thing, and have only found one way to justify writing one, and to persuage myself that it is not a complete waste of time. This is thatI will blogs as a journal of my adventures in life. It is like telling stories, and as I enjoy reading other peoples stories, I would like to try and write something that other people may be interested in.

My next adventure will be attempting to paddle round Anglesey with a group of friends next weekend. I'll let you know how it goes, and I look forward to reading your stories of adventure. Please feel free to send me an e-mail for any reason.

28/29 September 06: (The train to) Mallaig

I am camping in Mallaig, on the shore next to the car park, next to the train station. Today has been a long day. 9am I realised my train (from Edinburgh to Glasgow) was at 11.30am, and I still had a days worth of stuff to do. 11.30am, I manage to just get everything done in time, but miss the 11.30am train, so have to get the 11.45. I think all is well, so start repacking all my stuff more sensibly and securely (I am using Simons' (my sister Rachels' other half) bike trailer). A fantastic idea: I use my belt to secure the bouncing bags. After a chat with my seated neighour about our different walks of life, I step off the train, dragging my stuff behind me. I walked over to the display to check the train time, as I watched a train drive off. Shock horror...it was my train to Mallaig! Despair.

To cut a long story short, after 6 hours I was still in Glasgow waiting for the next train at 6.20pm, which I boarded in happiness. I was tired at first because I knew I hadn't had enough sleep. But I soon found stimulation in trying to catch the eye of the prettiest girl on the train (tall, slim, brunette, pretty, cute, etc...) who was facing me, a few seats down. Together with reading the paper, this entertained me for the whole journey. Shame it was dark - the scenery would have been fantastic. By the end of the journey (or at least her part), we were making eye contact more and more, practically starting into each others eyes. It had been a while since I done this with a girl. The tension was rising - I wanted to go and speak to her, but I couldn't find the guts - I was too afraid! In the end, she got off the train without us exchanging number/words, and I will probably never see her again. Maybe next time I will speak to that girl sitting opposite me on the train.

Which brings me closer to the present. I got off at Mallaig, asked the driver if he knew any campsites. So here I am, behind the wall, next to the car park, next to the train station, in my sleeping bag, on my Thermarest. I just cooked some beans (see photo) and am tired.

The reason I am here is to do my 4 star sea kayak training and assessment with Gordon Brown who owns and runs Skyak Adventures with his wife Morag in Isleornsay, Sleat Point, South Skye. I need to sleep as I am up early.

Night...

My first 'blog'

Hello

Well, what do I say? I'm 23, going into 5th year at Edinburgh Uni, doing mechancial engineering. Originally from the Isle of Barra in the Outer Hebrides. I think I'm generally an easy going person with liberal democratic political views. Quite open minded. Work as a sea kayak guide based in Barra in the summer. Want to leave Edinburgh and go somewhere else after I graduate - fancy living in Glasgow, or back on the West Coast, or maybe somewhere sunny!

So why am I starting a blog? Why does anyone start a blog? Look at my 3rd blog and I will write a quick paragraph. Before that, I have to write my second blog. Hmmm...you're confused!! Well, my reason is that I went on an adventure this weekend, and kept a journal with the aim of putting it in a blog, and in the second one, I wrote a paragraph on 'blogging' - enough said.

I am interested in what people get out of blogging, and why people do it. If you have ended up reading my blog this far, then firstly thank you, and secondly, why? I think that blogging can encourage very introverted activity, which could be a bad thing, but then it's useful for lots of other things as well. Le tme know what you think.

Kind regards,


Tom