I see the Netzaban bullet is pulled again. What about centrifugal force? What about inertia when changing attitudes? These tests mean nothing! Just put the bell crank anywhere you want.
I get a kick out of some people. Funny how all I ever hear about is CG and never the centrifugal force imposed. Must have come from a book in the 1960 TYS.
If you look at this picture
(http://www.clstunt.com/htdocs/dc/user_files/7458.jpg)
And imagine a engine on the front of it flying at 60 MPH circling to the left. Do you not think that all 3 points will want to line up? Do you not think that if everything was moved closer inline with the concentrated weight (engine) If would have less effect while turning left. Let alone up and down? I guess those hundreds of planes I have experimented with must all been wasted experiments.
was that a water dyno or a friction dyno? Or just a fish scale??
The idea was later used by James Watt to help market his improved steam engine. He had previously agreed to take royalties of one third of the savings in coal from the older Newcomen steam engines.[7] This royalty scheme did not work with customers who did not have existing steam engines but used horses instead. Watt determined that a horse could turn a mill wheel 144 times in an hour (or 2.4 times a minute). The wheel was 12 feet in radius; therefore, the horse travelled 2.4 × 2π × 12 feet in one minute. Watt judged that the horse could pull with a force of 180 pounds. So:
P = \frac{W}{t} = \frac{Fd}{t} = \frac{(180 \text{ lbf})(2.4 \times 2 \pi \times 12 \text{ ft})}{1 \text{ min}} = 32,572 \ \frac{\text{ft} \cdot \text{lbf}}{\text{min}}.
(http://upload.wikimedia.org/math/a/1/f/a1f88b48faa7319c28914b0f31d351a5.png)
This was rounded to an even 33,000 ft·lbf/min.[8]
Corn bread are square and pie are round
was that a water dyno or a friction dyno? Or just a fish scale??
The idea was later used by James Watt to help market his improved steam engine. He had previously agreed to take royalties of one third of the savings in coal from the older Newcomen steam engines.[7] This royalty scheme did not work with customers who did not have existing steam engines but used horses instead. Watt determined that a horse could turn a mill wheel 144 times in an hour (or 2.4 times a minute). The wheel was 12 feet in radius; therefore, the horse travelled 2.4 × 2π × 12 feet in one minute. Watt judged that the horse could pull with a force of 180 pounds. So:
P = \frac{W}{t} = \frac{Fd}{t} = \frac{(180 \text{ lbf})(2.4 \times 2 \pi \times 12 \text{ ft})}{1 \text{ min}} = 32,572 \ \frac{\text{ft} \cdot \text{lbf}}{\text{min}}.
(http://upload.wikimedia.org/math/a/1/f/a1f88b48faa7319c28914b0f31d351a5.png)
This was rounded to an even 33,000 ft·lbf/min.[8]
Corn bread are square and pie are round
It was an air-brake dynomometer which measured torque and was calibrated before use. The thrust stand that was also calibrated by known weights. I used a TNC Tachometer that is good to 5 ppm at 100,000 rpm
I am familiar with the notion of horsepower. And in any case, the difference between the two cases we investigated was a *factor of 2.5*, which means that a fine calibration was absolutely unnecessary to resolve the question at hand.
Conceptually the power is a measure of the rate at which work is done which leads to some interesting effects that would surprise the unwary. Work is the force x distance (horse lifting 550 lbs one foot, 550 ft-lbs of work) or in rotational terms the torque x the number of revolutions. Since it's the rate of work, it's the derivative of the work with respect to time, hence force x velocity (horse lifting 550 lbs by one foot in one second, 550 ft-lbs/second - same as 33,000 ft-lb/minute) or torque x the rpm.
Here's a horsepower calculation quiz question for the assembled group. A Saturn 1B rocket with a total of 1.5 million lbs of thrust. A launch it weighs 1.3 million lbs. What is the HP at the instant of release? It burns out after about 1 minute and a half at a velocity of 5000 feet per second and an altitude of 100,000 feet, and weighs 500,000 lbs. What is the horsepower at the instant of burnout? For sake of argument the thrust is the same in both conditions.
Same question except for airplanes. At launch on the ground, an airplane has a weight of 54 oz, a PA65, and a 13-4 3-blade, 10000 RPM, thrust is 4.5 lbs. What is the horsepower being applied to the airframe while being held? Then the airplane is released, and accelerates to a steady 80 feet/second in level flight after 3.5 seconds. At that condition, the drag of the airplane is 2.5 lbs, the engine RPM is 11,000. What is the horsepower being applied to the airframe in level flight? On the next flight, the prop is repitched to 3.5" and is otherwise the same. The ground launch RPM is now 11,000, the static thrust is now 5.0 lbs, and the airplane accelerates to 80 FPS in 2.5 seconds. What is the horsepower being applied to the airframe now?
Brett