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A Fair Price ?
May 21, 2012 09:37:15 #
photopop44
Loc: Roun Drock, Texas
jerryc41 wrote:
Aeordynamic question: I know that the shape of the wing causes a low pressure area above it, and that lifts the plane. So, when the plane is flying upsidedown, why doesn't it descend?
A Navy pilot, flight instructor, friend of mine told me that one of the laws of aerodynamics is "With enough horsepower (thrust) you can make the barn door fly".
May 21, 2012 09:51:13 #
I think a fair compromise would be to charge for the materials used and donate your time.
May 21, 2012 09:52:06 #
photopop44 wrote:
A Navy pilot, flight instructor, friend of mine told me that one of the laws of aerodynamics is "With enough horsepower (thrust) you can make the barn door fly".
jerryc41 wrote:
Aeordynamic question: I know that the shape of the wing causes a low pressure area above it, and that lifts the plane. So, when the plane is flying upsidedown, why doesn't it descend?
A Navy pilot, flight instructor, friend of mine told me that one of the laws of aerodynamics is "With enough horsepower (thrust) you can make the barn door fly".
Unlike the teardrop shape of say a 747, a fighter jet has a diamond shape wing. The lift properties are certainly not as good as the teardrop shape, but with enough thrust the jet wings also produce lift upside down.
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May 21, 2012 10:04:43 #
Buddy Bob wrote:
I have an associate who asked me if I could take s... (show quote)
There comes a time in everyone's life that we have to search inside our selves and do what we feel is right, I for one have done many things just out of the goodness of my heart, the rewards are what we make them to be.
May 21, 2012 10:20:36 #
If the guy insists that he pay you, just cover your expenses. You can write it off as a charitable donation. Or an even better trade, that releases a copyright license to you.
Just remember that this guy risked his life for you. You should take that into consideration.
Just remember that this guy risked his life for you. You should take that into consideration.
May 21, 2012 10:40:23 #
Buddy Bob wrote:
quote=jerryc41 quote=Buddy Bob He has plenty of ... (show quote)
We all know how much work it is to make old photos new again. Fifty bucks plus the price of the materials is fair price. And I'm going out on a limb myself and say this: Those with money are always looking for the cheapest way to get something done. He very likely thought you would do it for nothing and that's why he asked. Oh, and what is the definition of 'fair price'? ? Charge him what you want and don't feel guilty over it!
May 21, 2012 10:41:57 #
I admire the patriotism in this link but I think you guys Are full of it. When it gets right down to it time is all we have to sell. No matter what your job so why should this grown son of a Navy pilot get the work for free? If that were the case I believe that Nikon and Canon should send me free cameras because my great grandfather was a civil war hero(true). If you don't know what to charge then charge your regular hourly wage plus $5 an hour. That should cover your time and materials.
For those of you that want or feel the need to do something for free for active military families check out Operation Love Reunited at http://www.oplove.org/
They arrange for photographers to take photos of military personnel that are deploying and the photographers donate their time and materials. It's kind of nice to have a photo of your wife/husband and kids while you are deployed and it is a need for those wives/husbands and children that will never see their loved one again. There are a few of these organizations.
For those of you that want or feel the need to do something for free for active military families check out Operation Love Reunited at http://www.oplove.org/
They arrange for photographers to take photos of military personnel that are deploying and the photographers donate their time and materials. It's kind of nice to have a photo of your wife/husband and kids while you are deployed and it is a need for those wives/husbands and children that will never see their loved one again. There are a few of these organizations.
Check out Commercial and Industrial Photography section of our forum.
May 21, 2012 11:32:09 #
Lucian
Loc: From Wales, living in Ohio
jerry41 wrote:
"So that would be do-able in an F18 but not in a 747. Understood."
Actually it would be possible with the wing profile of a 747 too. All modern commercial jet aircraft have a very slim wing profile, that is what allows them to fly so fast, at over 500mph. They could not fly slow enough to take off and land though, just as they are. Therefore they have to to be fitted with flaps (at the back) and slats (at the front) which extend for slow flight, as in take off and landing.
The extension of these devices fools the air into thinking this is a wing with a large wing camber or large aerofoil which will allow slow flight but would not allow high speed flight, too much drag. By extending and lowering the slats at the leading edge of the wing and lowering the flaps at the trailing edge, it creates a large aerofoil shape which allows the aircraft to achieve slow flight.
Once airborne and as the aircraft airspeed increases, these devices slowly begin to retract until a speed has been reached whereby they are fully retracted and then the aircraft can just continue to increase its speed.
On it's descent after making its trip somewhere, at a predetermined airspeed the flaps begin to lower and the speed is further reduced and the slats begin to extend and lower at the front and the speed is again further reduced, until these are both fully extended. Then the wing can fly slow enough to make the approach and land. That is all the wheering and grinding noises you hear when starting the landing procedure as you are descending at the end of a flight. Very clever really design.
"So that would be do-able in an F18 but not in a 747. Understood."
Actually it would be possible with the wing profile of a 747 too. All modern commercial jet aircraft have a very slim wing profile, that is what allows them to fly so fast, at over 500mph. They could not fly slow enough to take off and land though, just as they are. Therefore they have to to be fitted with flaps (at the back) and slats (at the front) which extend for slow flight, as in take off and landing.
The extension of these devices fools the air into thinking this is a wing with a large wing camber or large aerofoil which will allow slow flight but would not allow high speed flight, too much drag. By extending and lowering the slats at the leading edge of the wing and lowering the flaps at the trailing edge, it creates a large aerofoil shape which allows the aircraft to achieve slow flight.
Once airborne and as the aircraft airspeed increases, these devices slowly begin to retract until a speed has been reached whereby they are fully retracted and then the aircraft can just continue to increase its speed.
On it's descent after making its trip somewhere, at a predetermined airspeed the flaps begin to lower and the speed is further reduced and the slats begin to extend and lower at the front and the speed is again further reduced, until these are both fully extended. Then the wing can fly slow enough to make the approach and land. That is all the wheering and grinding noises you hear when starting the landing procedure as you are descending at the end of a flight. Very clever really design.
May 21, 2012 11:38:44 #
Dontrain
Loc: Chicago suburb
My response to you will raise a firestorm of passionate disagreement, but...
For many years we were all taught the Bernoulli principle of velocity vs pressure in air flows. And, an airplane aloft is supported by the curved upper wing's shape creating some kind of low pressure-induced lift. Here is the heresy to this sacred doctrine: the Bernoulli theory as applied to an airplane wing lift is false. There is no gigantic low pressure hook pulling keeping the plane aloft. The air on the bottom of the wing is not pushing up to keep the plane straight and level.
Your observation is spot on; how can an asymmetrical airfoil fly inverted? The answer is not Bernoulli but Newton, his second law stating that for every action there is an equal and opposite reaction. As applied to an airplane wing it is the tilt of the wing upward into the airflow that re-directs the airflow downward and, as Newton stated, the opposite reaction is the upward thrust. Nearly all acrobatic aircraft wings are symmetrical, same curvature on top and bottom of the wing. How can these planes be flown in every conceivable configuration? Aeronautical engineers call the wing's pitch the Angle of Attack. An inverted airplane wing has to be intentionally flown level by pushing the stick forward to force the wing to pitch upward just the reverse of flying level right-side up. Here is the magic rule and it is not just my opinion: without a positive AoA sustained level flight is not possible. Most sub-sonic aircraft have a permanent special built-in AoA called the Angle of Incidence where the wing is intentionally pitched upward about 4 degrees with the aircraft center line level. This small angle allows an airplane to fly perfectly level and maintain altitude without the entire aircraft being pitched up slightly. There is no mystery here we see Newton at work every day in the pitched blades of a common window fan. It is a mystery to me how the Bernoulli theory became misapplied to and airplane wing for so many years. (Ask NASA)
Now the fun begins if my rant gets public, passionate opinions on both side of the discussion Bernoulli vs Newton. A dialogue not unlike the endless Nikon vs Canon debates, JPEG or RAW, etc.
dh
For many years we were all taught the Bernoulli principle of velocity vs pressure in air flows. And, an airplane aloft is supported by the curved upper wing's shape creating some kind of low pressure-induced lift. Here is the heresy to this sacred doctrine: the Bernoulli theory as applied to an airplane wing lift is false. There is no gigantic low pressure hook pulling keeping the plane aloft. The air on the bottom of the wing is not pushing up to keep the plane straight and level.
Your observation is spot on; how can an asymmetrical airfoil fly inverted? The answer is not Bernoulli but Newton, his second law stating that for every action there is an equal and opposite reaction. As applied to an airplane wing it is the tilt of the wing upward into the airflow that re-directs the airflow downward and, as Newton stated, the opposite reaction is the upward thrust. Nearly all acrobatic aircraft wings are symmetrical, same curvature on top and bottom of the wing. How can these planes be flown in every conceivable configuration? Aeronautical engineers call the wing's pitch the Angle of Attack. An inverted airplane wing has to be intentionally flown level by pushing the stick forward to force the wing to pitch upward just the reverse of flying level right-side up. Here is the magic rule and it is not just my opinion: without a positive AoA sustained level flight is not possible. Most sub-sonic aircraft have a permanent special built-in AoA called the Angle of Incidence where the wing is intentionally pitched upward about 4 degrees with the aircraft center line level. This small angle allows an airplane to fly perfectly level and maintain altitude without the entire aircraft being pitched up slightly. There is no mystery here we see Newton at work every day in the pitched blades of a common window fan. It is a mystery to me how the Bernoulli theory became misapplied to and airplane wing for so many years. (Ask NASA)
Now the fun begins if my rant gets public, passionate opinions on both side of the discussion Bernoulli vs Newton. A dialogue not unlike the endless Nikon vs Canon debates, JPEG or RAW, etc.
dh
May 21, 2012 11:40:38 #
I don't think the artistic value of the photo is an issue here. Isn't it memories we are trying to preserve? If you are trying to support you photography, then charge a fee. Probably should have determined that up front, but so be it. Each image is costing you around $1.82 to print (ink and paper). Take a look at photo retouchers on the net to see what they charge so you can back up your charges. I would expect you would charge less. Good luck.
May 21, 2012 11:41:06 #
The shape of an air foil determines the amount of lift, but all air foils (wings) have to have an "angle of atack" to develop lift (the leading edge is higher than the trailing edge). When the airplane is inverted, to maintain altitude, the piliot adjusts the attitude of the plane accordingly so that the angle of attack of the wind will produce lift on the bottom of the wing (which is now the top of the wing).
I am an aeronautical engineer
I am an aeronautical engineer
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May 21, 2012 11:44:26 #
Dontrain
Loc: Chicago suburb
My response to you will raise a firestorm of passionate disagreement, but...
For many years we were all taught the Bernoulli principle of velocity vs pressure in air flows. And, an airplane aloft is supported by the curved upper wing's shape creating some kind of low pressure-induced lift. Here is the heresy to this sacred doctrine: the Bernoulli theory as applied to an airplane wing lift is false. There is no gigantic low pressure hook pulling keeping the plane aloft. The air on the bottom of the wing is not pushing up to keep the plane straight and level.
Your observation is spot on; how can an asymmetrical airfoil fly inverted? The answer is not Bernoulli but Newton, his second law stating that for every action there is an equal and opposite reaction. As applied to an airplane wing it is the tilt of the wing upward into the airflow that re-directs the airflow downward and, as Newton stated, the opposite reaction is the upward thrust. Nearly all acrobatic aircraft wings are symmetrical, same curvature on top and bottom of the wing. How can these planes be flown in every conceivable configuration? Aeronautical engineers call the wing's pitch the Angle of Attack. An inverted airplane wing has to be intentionally flown level by pushing the stick forward to force the wing to pitch upward just the reverse of flying level right-side up. Here is the magic rule and it is not just my opinion: without a positive AoA sustained level flight is not possible. Most sub-sonic aircraft have a permanent special built-in AoA called the Angle of Incidence where the wing is intentionally pitched upward about 4 degrees with the aircraft center line level. This small angle allows an airplane to fly perfectly level and maintain altitude without the entire aircraft being pitched up slightly. There is no mystery here we see Newton at work every day in the pitched blades of a common window fan. It is a mystery to me how the Bernoulli theory became misapplied to and airplane wing for so many years. (Ask NASA)
Now the fun begins if my rant gets public, passionate opinions on both side of the discussion Bernoulli vs Newton. A dialogue not unlike the endless Nikon vs Canon debates, JPEG or RAW, etc.
dh
For many years we were all taught the Bernoulli principle of velocity vs pressure in air flows. And, an airplane aloft is supported by the curved upper wing's shape creating some kind of low pressure-induced lift. Here is the heresy to this sacred doctrine: the Bernoulli theory as applied to an airplane wing lift is false. There is no gigantic low pressure hook pulling keeping the plane aloft. The air on the bottom of the wing is not pushing up to keep the plane straight and level.
Your observation is spot on; how can an asymmetrical airfoil fly inverted? The answer is not Bernoulli but Newton, his second law stating that for every action there is an equal and opposite reaction. As applied to an airplane wing it is the tilt of the wing upward into the airflow that re-directs the airflow downward and, as Newton stated, the opposite reaction is the upward thrust. Nearly all acrobatic aircraft wings are symmetrical, same curvature on top and bottom of the wing. How can these planes be flown in every conceivable configuration? Aeronautical engineers call the wing's pitch the Angle of Attack. An inverted airplane wing has to be intentionally flown level by pushing the stick forward to force the wing to pitch upward just the reverse of flying level right-side up. Here is the magic rule and it is not just my opinion: without a positive AoA sustained level flight is not possible. Most sub-sonic aircraft have a permanent special built-in AoA called the Angle of Incidence where the wing is intentionally pitched upward about 4 degrees with the aircraft center line level. This small angle allows an airplane to fly perfectly level and maintain altitude without the entire aircraft being pitched up slightly. There is no mystery here we see Newton at work every day in the pitched blades of a common window fan. It is a mystery to me how the Bernoulli theory became misapplied to and airplane wing for so many years. (Ask NASA)
Now the fun begins if my rant gets public, passionate opinions on both side of the discussion Bernoulli vs Newton. A dialogue not unlike the endless Nikon vs Canon debates, JPEG or RAW, etc.
dh
May 21, 2012 11:44:56 #
May 21, 2012 11:45:33 #
Lucian
Loc: From Wales, living in Ohio
brokeweb wrote:
"Just remember that this guy risked his life for you. You should take that into consideration."
This is true therefore, he also did it for you as well, so why don't you consider sending a small cash donation to cover your gratitude as well, to the OP to help him with his expenses? That would seem the correct thing to do, because from your posting, that too should be taken into consideration.
Soldiers do risk their lives for the safety of the general public but so do some policemen and firemen but you do not see these people getting everything for free everywhere.
I am sure there is no one amongst us who does not feel thanks for all three of these occupations, but at the same time, we live in a world where we all must earn something to be able to survive (pay our biils and buy food) and therefore it is no insult to ask for payment for your time in doing a job for them, just as they do their job but also expect to be and get paid for doing it.
You are free to offer a discount but it does not have to be free and I'm sure most soldiers would not expect it to be free, if you were to ask them. They wish to come back into society as an equal not a worshipped god or icon. Therefore give them that respect.
"Just remember that this guy risked his life for you. You should take that into consideration."
This is true therefore, he also did it for you as well, so why don't you consider sending a small cash donation to cover your gratitude as well, to the OP to help him with his expenses? That would seem the correct thing to do, because from your posting, that too should be taken into consideration.
Soldiers do risk their lives for the safety of the general public but so do some policemen and firemen but you do not see these people getting everything for free everywhere.
I am sure there is no one amongst us who does not feel thanks for all three of these occupations, but at the same time, we live in a world where we all must earn something to be able to survive (pay our biils and buy food) and therefore it is no insult to ask for payment for your time in doing a job for them, just as they do their job but also expect to be and get paid for doing it.
You are free to offer a discount but it does not have to be free and I'm sure most soldiers would not expect it to be free, if you were to ask them. They wish to come back into society as an equal not a worshipped god or icon. Therefore give them that respect.
May 21, 2012 11:46:16 #
frenchcoast wrote:
quote=Festina Lente quote=jerryc41 Aeordynamic q... (show quote)
REALLY??? even in threads I'm not participating in you have to take digs at me? other members have to send me a pm to tell me to take a look?
I have reported this to the admin, I think you are nothing more than a bully.
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