|Posted by Team Manager on May 25, 2015 at 7:25 AM||comments (0)|
The understanding and definition of Propeller.
I would like to start with the definition of the word Propeller to which in the world of Hoverpod® is something that is often misused. I have hear the driving force of the Hoverpod® called a Fan, Turbine and many other terms but in truth it is a propulsion system and to that end defines it as a Propeller.
The definition and description of the propeller as well as this history of the propeller has a varied and interesting history and some of which is defined below:
The twisted airfoil (aerofoil) shape of an aircraft propeller was pioneered by the Wright brothers. While some earlier engineers had attempted to model air propellers on marine propellers, the Wrights realized that a propeller is essentially the same as a wing, and were able to use data from their earlier wind tunnel experiments on wings. The Wrights introduced a twist along the length of the blades. This was necessary to maintain a more uniform angle of attack of the blade along its length. Their original propeller blades had an efficiency of about 82%, compared to the 90% of modern propellers. Mahogany was the wood preferred for propellers through World War I, but wartime shortages encouraged use of walnut, oak, cherry and ash.
Alberto Santos Dumont was another early pioneer, having designed propellers before the Wright Brothers (albeit not as efficient) for his airships. He applied the knowledge he gained from experiences with airships to make a propeller with a steel shaft and aluminium blades for his 14 bis biplane. Some of his designs used a bent aluminium sheet for blades, thus creating an airfoil shape. They were heavily undercambered, and this plus the absence of lengthwise twist made them less efficient than the Wright propellers. Even so, this was perhaps the first use of aluminium in the construction of an airscrew.
Originally, a rotating airfoil behind the aircraft, which pushes it, was called a propeller, while one which pulled from the front was a tractor. Later the term 'pusher' became adopted for the rear-mounted device in contrast to the tractor configuration and both became referred to as 'propellers' or 'airscrews'.
The understanding of low speed propeller aerodynamics was fairly complete by the 1920s, but later requirements to handle more power in a smaller diameter have made the problem more complex.
A well-designed propeller typically has an efficiency of around 80% when operating in the best regime. The efficiency of the propeller is influenced by the angle of attack (α). This is defined as α = Φ - θ, where θ is the helix angle (the angle between the resultant relative velocity and the blade rotation direction) and Φ is the blade pitch angle. Very small pitch and helix angles give a good performance against resistance but provide little thrust, while larger angles have the opposite effect. The best helix angle is when the blade is acting as a wing producing much more lift than drag. Angle of attack is similar to advance ratio, for propellers.
A propeller's efficiency is determined by
Propellers are similar in aerofoil section to a low-drag wing and as such are poor in operation when at other than their optimum angle of attack. Therefore some propellers use a variable pitch mechanism to alter the blades' pitch angle as engine speed and aircraft velocity are changed.
The three-bladed propeller of a light aircraft: the Vans RV-7A
A further consideration is the number and the shape of the blades used. Increasing the aspect ratio of the blades reduces drag but the amount of thrust produced depends on blade area, so using high-aspect blades can result in an excessive propeller diameter. A further balance is that using a smaller number of blades reduces interference effects between the blades, but to have sufficient blade area to transmit the available power within a set diameter means a compromise is needed. Increasing the number of blades also decreases the amount of work each blade is required to perform, limiting the local Mach number - a significant performance limit on propellers.
A propeller's performance suffers as the blade speed nears the transonic. As the relative air speed at any section of a propeller is a vector sum of the aircraft speed and the tangential speed due to rotation, a propeller blade tip will reach transonic speed well before the aircraft does. When the airflow over the tip of the blade reaches its critical speed, drag and torque resistance increase rapidly and shock waves form creating a sharp increase in noise. Aircraft with conventional propellers, therefore, do not usually fly faster than Mach 0.6. There have been propeller aircraft which attained up to the Mach 0.8 range, but the low propeller efficiency at this speed makes such applications rare.
There have been efforts to develop propellers for aircraft at high subsonic speeds. The 'fix' is similar to that of transonic wing design. The maximum relative velocity is kept as low as possible by careful control of pitch to allow the blades to have large helix angles; thin blade sections are used and the blades are swept back in a scimitar shape (Scimitar propeller); a large number of blades are used to reduce work per blade and so circulation strength; contra-rotation is used. The propellers designed are more efficient than turbo-fans and their cruising speed (Mach 0.7–0.85) is suitable for airliners, but the noise generated is tremendous (see the Antonov An-70 and Tupolev Tu-95 for examples of such a design).
Since the 1940s, propellers and propfans with swept tips or curved "scimitar-shaped" blades have been studied for use in high-speed applications so as to delay the onset of shockwaves, in similar manner to wing sweepback, where the blade tips approach the speed of sound. The Airbus A400M turboprop transport aircraft is expected to provide the first production example: note that it is not a propfan because the propellers are not mounted directly to the engine shaft but are driven through reduction gearing.
The purpose of varying pitch angle with a variable-pitch propeller is to maintain an optimal angle of attack (maximum lift to drag ratio) on the propeller blades as aircraft speed varies. Early pitch control settings were pilot operated, either two-position or manually variable. Following World War I, automatic propellers were developed to maintain an optimum angle of attack. This was done by balancing the centripetal twisting moment on the blades and a set of counterweights against a spring and the aerodynamic forces on the blade. Automatic props had the advantage of being simple, lightweight, and requiring no external control, but a particular propeller's performance was difficult to match with that of the aircraft's powerplant. An improvement on the automatic type was the constant-speed propeller. Constant-speed propellers allow the pilot to select a rotational speed for maximum engine power or maximum efficiency, and a propeller governor acts as a closed-loop controller to vary propeller pitch angle as required to maintain the selected engine speed. In most aircraft this system is hydraulic, with engine oil serving as the hydraulic fluid. However, electrically controlled propellers were developed during World War II and saw extensive use on military aircraft, and have recently seen a revival in use on homebuilt aircraft.
On some variable-pitch propellers, the blades can be rotated parallel to the airflow to reduce drag in case of an engine failure. This uses the term feathering, borrowed from rowing. On single-engined aircraft, whether a powered glider or turbine-powered aircraft, the effect is to increase the gliding distance. On a multi-engine aircraft, feathering the propeller on a failed engine helps the aircraft to maintain altitude with the reduced power from the remaining engines.
Most feathering systems for reciprocating engines sense a drop in oil pressure and move the blades toward the feather position, and require the pilot to pull the propeller control back to disengage the high-pitch stop pins before the engine reaches idle RPM. Turboprop control systems usually utilize a negative torque sensor in the reduction gearbox which moves the blades toward feather when the engine is no longer providing power to the propeller. Depending on design, the pilot may have to push a button to override the high-pitch stops and complete the feathering process, or the feathering process may be totally automatic.
In some aircraft, such as the C-130 Hercules, the pilot can manually override the constant-speed mechanism to reverse the blade pitch angle, and thus the thrust of the engine (although the rotation of the engine itself does not reverse). This is used to help slow the plane down after landing in order to save wear on the brakes and tires, but in some cases also allows the aircraft to back up on its own - this is particularly useful for getting floatplanes out of confined docks. See also Thrust reversal
|Posted by Team Manager on June 4, 2013 at 9:50 AM||comments (0)|
It's finally arrived, the sun has been out for over a week and it's here to stay......"for a while anyway". The motorwary miles are now begining to clock up with many a trip south to the coast's both here in the UK as well as some strategic locations on the mediteranium. For a variety of reasons, I'm not permited or cleared to say just where for now......................."it's nice though and rather posh".
The well kept secret surrounding the powerplant appears to be finally out and whilst I'm not permitted to speak openly,it's clear the secret is no longer a secret. The rumours about an out of place "Barrell" and an almost predictable problem have been dealt with by our associates from Italy in two key areas, firstly a short term solution and more importantly a long terminal solution of which should finally burry the problem for good.
F1 Hoverpod Ltd and it's associate members are keen to share progress and something to which is now looking increasingly likely "although not yet set in stone" is the potential or possibility of a move away from mass production in the UK but to a locationg with easy access to the EU market place but without the problems associated with the EU rules and minefileds, I will share the updates as and when they come my way.
We have started to up-date some of the web sites and you may well be keen to visit the following to keep updated with happenings:
https://www.facebook.com/pages/F1-Hoverpod-Ltd/301120223250816" target="_blank" rel="nofollow">Facebook
Keep watching out for updates as we do have a very exciting year ahead with lots to share with you.
|Posted by Team Manager on October 17, 2012 at 10:45 AM||comments (0)|
It may be all cold grey and dismal outside but the hearts and minds of team F1 Hoverpod Racing and simply glowing with excitement with so many possitive happenings due over the next few months.:/
I made you all a promise to which I intend to keep to the best of my ability and that commitment was to share with you the good news as and when I knew the information myself, we here is something to excite the very best of you. The logo to which is recognised as the official logo for F1 Hoverpod Racing has now gained legal protection under the laws of "Trade Mark Registration" and starts the first step forward of many new developments within the F1 Hoverpod group of companies.
Please feel free to join our Facebook sites and keep a watch over the blogs for some news postings over the following weeks.
|Posted by Team Manager on April 4, 2012 at 6:10 PM||comments (0)|
The summer was here in Central Europe and record's were broken in Scotland with the hotes't March records being beaten on an almost daily basis...............but Wait. This morning was a hasty reminder by the Weather God that they were still in controll. It was winter iwht a vengence and snow almost everywhere in Hoverpod land. The conditions on the roads were at best trecherous and with many main roads blocked due to snow and wind, it all built up to a rather testing morning.
The rapid change in the weather condition brought home the reality that perhaps the scientist's who have all been warning us about the world warming up should be taken serious but then to counter the argument the scpetics keep asking for the evidence that it is Mankind who has created the problem and are always so eager to point out thet the world has always had periods of warmth followed by even longer periods of cold, so what can we all do about this confusion in order that we can do the right thing to suit every issue and event and provide a platform of comfort for all. Well there is something we can all in order dispell the confusion in some way and I'm proud to confirm that F1 Hoverpod Ltd for their part are doing all they can to retain the excitement within the sport with the satisfaction that they have pleased the environmental supporters by developing techniques and technology which enables the Hoverpod to reduce it's Co2 emissions by up to 80% without any reduction of power.
The world of Motor Sport is a technology driven activity to which is fundementally driven by the excitiment and attraction associated with high speed racing, the commitment shown by the team to retain all of this excitiment whilst developing systems in which to help keep the planet a good place to enjoy such leisure activities is something of which I for one and emensely proud to be associated with and long may Motor Sport continue with a compromise and balance for all to enjoy for a long time to come.
|Posted by Team Manager on March 29, 2012 at 10:35 AM||comments (0)|
March 2012 and News from team F1 Hoverpod Ltd.
It's hard to believe it but it's still only March 2012 and I am pinching myself in order to waken up and find it's really cold outside, the truth is it's a heatwave and it's spread across europe in a big way.
The trip started with a quick hop over the chanel by ferry to Calais and a very long drive through Belgium, Holland and finally to arrive in Germany one of my favourit countries. The night driving was never an easy task and the outside temprature was close to freezing but when the sun climbed out of bed, the frost on the ground soon vanished and replaced the cold air with a very comforting heat that I can only describe as weird for March.
As some of you have been following us on our facebook page, it would not be productive to repeat it all on here but for those who are not aware, we covered quite a lengthy area of europe in little more that 12 days, the highlight for me was a long weekend in Monaco where we had nothing to do except relax......oh and enjoy the view. I did meet up with a chap who was proudly showing of his type 35 Bugatti which as anyone who knows me will tell you, this is my all time fave.
After a quick trip over the boarder to the land of very expensive coffee, chocolate and just about everything, a lengthy meeting with it's other famous institutions took most of our time up.
The trip back through the mountains was entertaining and as expected a little testing for the driver and with additional meetings in Germany & Poland, there was still much ahead of us by way of driving.
The tour of a big brand name in motor manufactur was a very interesting day and I was simply fascinated with the robots and computerised systems in place and clearly shows the comitment to never compromise on quality and always ensure that the best of the very best is produced every day of the week.
I am anticipating some very exciting news shortly and will as soon as cleared to do so share this information with you all, I understand your eagerness to hear something soon and will deliver to you all the information as soon as permited to do so.
|Posted by Team Manager on March 5, 2012 at 6:55 PM||comments (0)|
The start of 2012 got the team at F1 Hoverpod Ltd off to what we all expected was going to turn into a great year, especially after the great news in regards to the published site known as Ripoff Report. I suppose that anything good after the result we had with the big 3 search engines would almost fall into insignificance after such a result but "Not at all". I know whats just around the corner and whilst I cant say right now, the news that is about to break will excite the very best of you so be patient.
Friday was an interesting day with a guided tour of a car manufacturers show case centre and it was a very impressive time as well as being very enjoyable for all who came. I'm not able to say who or where that took place but you will all see them on the TV in Bahrain shortly and our very best wishes to them all.
Stay tuned as we do have some breaking news ready to publish shortly.
|Posted by Team Manager on January 26, 2012 at 10:30 AM||comments (0)|
Well, it was always going to be a huge story if and when it broke but "Cor Blimey" has the phone been busy today at team HQ.
F1 Hoverpod Ltd and it's partner company F1 Hoverpod Racing Ltd were the vicims of a witten attack by people with what has been described today as having a vicious streak who wrote comments of a nature considered to be libel and slanderous and posted those comments on a web site known for it's almost Blackmail nature known as Ripoff Report. Today I can announce that through cooperation and support of the three major search engine opperators, not only have the identities of the perpertrators been identified but the comments and statements have been proven to be a total fabrication.
I wish to formally acknowledge the help and kind assistance by all three (3) search engine opperators who worked there way through so much technical data to locate the source of the postings and for the appointment of such a highly respected University such as Harvard to appoint the pannel from Chilling Effects to arbitrate the evidence and conclude that not one shred of information was based upon fact and that the whole exercise was a determined attempt to discredit F1 Hoverpod Ltd and F1 Hoverpod racing with the maximum impact. The web site to which I refer is known as Ripoff Report and can be found at www.ripoffreport.com and is owned, managed a run by one Edd Magedson who's own personal record can be best summed up by the people who have wrote so much about this chap and his credentials, I found this and discovered the chap has more recods than Elvis at http://www.edmagedson.com/
On the face of it, F1 Hoverpod Ltd have had a testing time but then we are all here and have only ever been questioned by one web site posting, the perpetrator of which is now being tracked down by the lawyers ready for the delights of what comes next, for the team at F1 Hoverpod, it's been a real test of belief and inner strength to which only the toughest of tough come through but it's true to say that the whole team are truly releived the whole experience is behing us and we can go forward with the knowing the truth came out in the end.
A Huge Thank You to Bing.com, Yahoo and Google for their cooperation in complying with the legal requirement of the countries to which the law of Libel is recognised and for the removal from said search engines any reference of such comments from future viewing.
I always say that honest pays in the end. Watch for the Reaction in the other corner with lawyers now appointed.
|Posted by Team Manager on December 28, 2011 at 7:15 AM||comments (1)|
The Magical Christmas Day is now behind us and the effects of the F1 Hoverpod® Ltd annual party are for now somewhere in the distance to the rear but looming on the horizon is the event to which I for one always show preference to which is the binging in of a New Year.
The members and colleagues at the F1 Hoverpod® group all look forward to making a new year’s resolution to which by February almost 90% will have reverted back to old habits and ways as they did last year.
There is a very serious side to the team at F1 Hoverpod® Ltd to which much of the focus is upon the world famous F1 Hoverpod® Racing team who are as we speak preparing the ground for strategy and technique for the upcoming year. As with Most Motor Sports and Hoverpod® pilot and his crew have to be up to the job to which demands a regime of physical fitness in order to cope with the stress’s when racing and because of the way a Hoverpod® has the ability to travel across almost any flat surface at super fast speed, this creates extra commitment on the body to which some lesser Motor Sports don’t necessarily require, the result being that a sport such as F1 Hoverpod® Racing can provide all the excitement of traditional Motor Sport with the extra thrills and demands such as high speed action on Ice, Snow, Mud or even Sand.
The New Year brings in some new members to the F1 Hoverpod® Ltd Management Board of Control as well as some expected announcements in relation to developments at F1 Hoverpod® Racing of which is extremely exciting and will have some official announcements in the spring.
For now, we are but a few days away from the New Years Eve celebrations and we have a skeleton team in over the festive period, much of the staff are enjoying an extended period away with family and friends and we should all be back together to welcome the new year in (albeit a little early) for some team bonding and social activities on Thursday, I’m sworn to secrecy as to where the bash is happening as we always have gate crashers wishing to join in and as such we keep this a closely guarded secret.
All it leaves me left to do is Wish You All A Happy New Year and to Look Forward To Welcoming You All Back In The New Year.
Happy New Year From All At F1 Hoverpod® Ltd.
|Posted by Team Manager on December 12, 2011 at 8:25 AM||comments (0)|
December is here again and for most people round the world this spells a busy period of the long build up to Christmas.
For the Team at F1 Hoverpod Racing it spells a period of madness, dressing up in fancy dress and playing with a Hoverpod on ice and snow.
Many people are aware of the ability of the Hoverpod to travel on land and water but quite often the thought that it can travel across snow and ice is for most parts overlooked. This not only allows for some extra axcitiment but also prepares the ground for a super safety & rescue craft with the ability to travel at high speed across most surfaces withought hinderence.
Check out www.f1hoverpod.com where you will find a link to "view our movies" that shows an indepth look at the properties of the Hoverpod. If you are a keen Motor Sport enthusiast, you may find a sneek look at www.f1hoverpodracing.com is something you may find quite exciting.
The Team @ F1 Hoverpod Racing has expressed that I mention a huge thank you from them for all the support and encouragement throughout the year, the comments on the blogs and through the forum have been nothing short of inspiring and on many occasions very funny, for now the team are all dressed in fancy dress to embrace the Christmas spirit. We have a Rudholf, an Elf, a Santa and as always a Fairy (Colin a strange Man).
All it leaves me left to do is Wish You All A Very Merry Christmas from All at F1 Hoverpod Racing.
|Posted by Team Manager on December 5, 2011 at 6:45 PM||comments (0)|
It's December 2011 and in Hoverpod land it's very cold outside. It's a good time for checking out the stability of the product on extreme conditions such as snow and ice although fining a volunteer to go outside and test the product is perhaps the most difficult task for today.
The whole team are all in the spirit of Christmas and we have all taken the occasional moment to reflect upon what a year it's been at Team F1 Hoverpod. There have been a few suprises with the securing of URL'S such as www.f1hovercraft.com and www.f1hovercraftracing.com and the huge interest shown from the far East and as such two new web site address's were required and I recomend you to take a look at the following at some point:
The daily routine of pushing forward no matter what the obstacle is in front continues for all at F1 Hoverpod Ltd Team Camp and we are all excitied about the future and the early build up of excitiment for 2012, I'm not permitted to say too much at this moment but you can rest assured that when the press office confirms and clears the news, it will be posted for all to see and I can share with you it's truly exciting news and something you are all waiting to hear.
All it leaves me to do at this moment is to Wish All of our supporters and fans a wonderfull Christmas and to spare a thought for those less fortunate that ourselves at this time of year.
Merry Christmas to All.