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Showing posts with label aerodynamics. Show all posts
Showing posts with label aerodynamics. Show all posts

Wednesday, 9 November 2011

Droning on about UAV's

Observer South African UAV in flightImage via Wikipedia
The Unmanned Aerial Vehicle, UAV, or more commonly known as Drones are becoming ever more present in today’s world. Mainly used in the military for all types of purposes the UAV is starting to find itself being used in more civilian uses like policing.

Using UAV's for police work is not necessarily new as some cities have trialled the use of them before. Most of the trial periods though failed either due to funding or the fact that the drone crashed! There is hope though for UAV to be used for policing and for other uses.
In the South African context with our high crime rate and porous borders the use of drones could well be part of the solution. Funding is always going to be a problem but the cost of UAV's is slowly coming down. For most part the cost of operating a drone was only slightly cheaper than crewed aircraft. As the technology improves so does the cost come down.

Denel, the South African arms manufacturers, have developed a UAV called the Seeker 400. This UAV is capable of flying for 16 hours without re-fuelling in any weather and be controlled from a computer hundreds of kilometres away. Granted this has been developed for military purpose but it could easily be adapted for civilian purposes.

Uses

We could have these UAV’s patrolling crime hotspots with camera’s and when something happens it can track the criminals until either a helicopter is chasing or ground crew are in pursuit. It would be able to monitor protests from above giving riot police information on where to be deployed.  Being able to monitor troublesome spots for up to 16 hours would be a huge tactical advantage to police.
Mótmæli vörubílstjóra 23. apríl 2008Image via Wikipedia

Other uses would be in the fight against poachers who are killing rhino’s for their horns. These drones could be placed above nature reserves and monitor both rhino and detect poachers allowing ground and air teams to move in on them.

In a recent article SARS, South Africa Revenue Service, complained that the borders of the country are vulnerable. Apparently the 4800km land border is not under surveillance and allows people to just walk across and even fly due to inadequate radar coverage. Our shoreline also suffers the same fate.  Surely a couple of well placed drones would go a long way to tighten border security.

Granted some people will probably say that their rights are being infringed by these drones circling above them and being under surveillance but in the end I would believe it would not be a big issue if used for the purposes it is intended for.

Failure
Of course the use of UAV’s could always fail like the pilot drone used in the UK. It assisted in only one arrest before it crashed. You can read the full story here. Having looked at the pictures of this drone it looked more like a toy controlled with an iPhone than a police issue UAV.

There is the opposite extreme though. Police in Texas are now putting weapons onto their drones? I personally do not think this a wise move especially if the drone crashes then the weapons will be easy pickings? Rather stick to camera’s and thermal imaging and whatever else can be crammed into these awesome flying vehicles.
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Tuesday, 1 November 2011

Building towards a supersonic Electric Aeroplane

The eGenius electric aircraft recently participated in the Comparative Aircraft Flight Efficiency (CAFE) Green Flight Challenge. It was sponsored by Google, at the Charles M. Schulz Sonoma County Airport in Santa Rosa, Calif. on Monday, Sept. 26, 2011. NASA and CAFE Foundation have the goal to advance technologies in fuel efficiency and reduced emissions with cleaner renewable fuels and electric aircraft.

The Green Flight Challenge had 13 teams competing for the $1.65 million prize provided by NASA. This is the largest purse for any aviation event in history. In order to win the prize teams needed their  aircraft must fly 200 miles in less than two hours and use less than one gallon of fuel per occupant, or the equivalent in electricity.

In the end only three teams successfully completed the aircraft and flight qualification requirements. The winner was team Pipistrel-USA.com, a four seater electric aircraft called the Taurus 4, with an almost unbelievable 403.5 passenger miles per gallon efficiency over a flight distance of 200miles. Twice that of the already efficient piston powered aircraft in the same competition.

The e-Genius team won the Lindbergh Electric Aircraft Prize (LEAP) for the quietest aircraft with a peak take off noise of just 59.5 dBA (A normal conversation ranges between 80-85 dBA). This brings the potential capability of having aircraft quiet enough to land near houses and businesses without the noise aggravation. Good news for those living and working near airports.

Some other interesting facts from the Green Flight Challenge:
  • There were 20 exhibitors showing off their visions of the greener aviation future
  •  Pipistrel G-4 achieved 403.5 PMPG over its 200 mile flight
  • The eGenius achieved 375.8 PMPG
  • The winning check for $1.3 million is the equivalent to a Nobel prize winner (1 million Euros)
  • The G-4 could be charged for a two-hour flight at a cost of $7. (based on 8c for a KW)
  • Receiving their electricity from geo-thermal powered generators on nearby peaks in the Geyserville area, CAFE’s fliers flew “green”
  • A future challenge is now to create a supersonic Electric aircraft.
The Green Flight challenge 2011 has heralded a new change in aviation history. The future technology of aviation was most likely born at this event.
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Tuesday, 27 September 2011

A dream-liner of the sky

Boeing have officially handed over the first 787 Dreamliner to Japan's All Nippon Airways. The 787 programme began back in 2003 and will compete with their European rivals Airbus A350. The Dreamliner is "The most technologically advanced commercial airplane in history" according to Boeing 787 Chief Project Engineer Mike Sinnett.
Artist impression of Boeing 787-9 Dreamliner.Image via Wikipedia

The Dreamliner is a twin-engine, bendy winged, widebody craft that has raised the bar for fuel efficiency. Some 50 percent of the weight of the 787 airframe is lightweight carbon-fibre composites that could, Boeing says, help reduce fuel costs by 20 percent. Whether travellers will benefit from the lower fuel consumption will depend on how greedy the airlines are.

The Dreamliner was in part designed to be a panacea to passenger discomfort. Numerous new technologies and design effects have allowed the Dreamliner to become more passenger friendly. Boeing spent years researching their customer's customer, us. Their research resulted in a number of design tweaks and improvements.
787 mockupImage via Wikipedia

The initial boarding was found to be of utmost importance so Boeing worked with artists and architects to create arched entranceways which provide a relaxing contrast to the "stress of pre-flight security." Not only this but you can expect roomier seats, more storage and larger, manually dimmable windows. Even economy class will see some luxury additions, with a bar, female-only lavatories and Panasonic entertainment on demand for every passenger.

Older technology has also been re-purposed such as LED lights installed in the 787 cabin, allowing the ceiling to appear higher, lighting can be controlled to make the transition between day and night easier.

One of the biggest technological advancements is the cabin pressure within the Dreamliner. The Dreamliner allows for a more comfortable cabin pressure. The pressure inside the cabin is the equivalent of 6,000 feet and not the normal 8,000 feet. The air can be recycled more frequently due to the composite body of the plane. There is also more humidty in the air reducing symptoms related to dryness.

The single aisled Dreamliner, seats between 210-290 passengers and has an asking price of $202m. Boeing estimate the potential market to be about 3300 units. Boeing already has 821 orders worth $150bn for the plane in the pipeline. Although it has endured many delays from its start to now, Boeing hope to build up to 10, 787 Dreamliners per month by the end of 2013.

For those that are interested Boeing shares, were up 3.3 percent at $61.49 on Monday morning on the New York Stock Exchange.


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Wednesday, 17 August 2011

13,000 MPH plane crash

DARPA, the Defense Advanced Research Projects Agency, attempted to fly the fastest aircraft ever built. The experimental aircraft is called the Falcon Hypersonic Technology Vehicle 2 (HTV-2). This vehicle is designed to be part of the US defence force "Prompt Global Strike" programme.

The HTV-2 is designed to be able to strike anywhere in the world within 60 minutes. To be able to achieve this feat an aircraft would need to fly at 13,000MPH. The HTV-2 would be launched and successfully placed into desired trajectory by using a separate vehicle. After successfully separating from the launch vehicle the HTV-2 would transition into MACH 20 aerodynamic flight.

On August, 11, 2011, the HTV-2 was launched and separated from the launch vehicle, Minotaur IV. More than nine minutes of data was captured before an anomaly caused loss of signal. This anomaly has puzzled scientists and they are trying to understand what went wrong. It appears that the HTV-2 crashed into the Pacific Ocean along its planned flight plan.

“Here’s what we know,” said Air Force Maj. Chris Schulz, DARPA HTV-2 program manager and PhD in aerospace engineering.  “We know how to boost the aircraft to near space.  We know how to insert the aircraft into atmospheric hypersonic flight.  We do not yet know how to achieve the desired control during the aerodynamic phase of flight.  It’s vexing; I’m confident there is a solution. We have to find it.”

There are a couple of technical areas of concern that DARPA are working on to get the HTV-2 operational. The areas are aerodynamics, aero thermal, guidance, navigation and control. When DARPA do manage to solve these vexing problems it is certainly going to make the US defence that much more powerful than it is already.