Friday, July 30, 2010

Where is the FCC?

Where is the FCC?

Why are they not controlling the enormous and irritating commercial content of today's broadcast television?

I know that broadcasters must make money selling air time for commercials, but those airwaves belong to the public, not the corporations. Profit for corporations is not the only interest requiring protection here. Every single broadcast license still contains language about broadcasting in the "public interest".

I just stopwatch-timed program vs commercial content for tonight's ABC World News Tonight broadcast. There was 20 minutes and 15 seconds of program content vs 9 minutes and 45 seconds of commercial content, in a 30 minute prime time slot. That is 33% commercial content and 67% program content. Most of the commercials (more than half the air time) were in the second half of the overall program: I timed the first 12 minutes (40% of the time slot) as continuous news.

When I was much younger in the mid 1960's, that ratio was quite different. Prime time program content was around 51 minutes of every hour, while commercials were only 9 minutes. That's 15% commercials in prime time. In those days, we all believed that there were FCC regulations limiting prime time commercial content to those levels.

Apparently, that situation has changed, for commercial content is now a little more than double the 1965-ish value. Not very many years ago, I heard an FCC official claim that there never were any rules about commercial content in prime time. Based on my actual life experiences, I do not believe that statement.

If there are indeed no rules on commercial content now, then the FCC repealed in recent years their own regulations, to favor corporate profits over the public interest. Yet, the rationale for the very existence of the FCC as a government agency is in fact protection of the public interest, with respect to the airwaves owned by that very public.

So, I repeat: where is the FCC, and who are they really working for?

Friday, July 23, 2010

More Strap-On Pod Ramjet Engine Data

These images are "extras" computed from the strap-on pod ramjet performance-map data. That data covers flight Mach numbers from 1.5 to 6, and altitudes from 5000 feet to 100,000 feet. In an earlier post, the overall energy conversion efficiency was correlated vs flight Mach as almost independent of altitude. This has potential application to rough-sizing vehicles in "back-of-the-envelope" (BOE) analyses.

In this post, the pod thrust is correlated vs flight Mach and flight altitude in two graphs. The first shows net jet thrust vs Mach number parametric on altitude. Similar to the efficiency, these figures are very insensitive to altitude. The average model through the center of the data is a simple quadratic fit:

Fnj / Fnj at M4 = -.068 (M - 4)^2 + .028 (M - 4) + 1.00

The second shows the net jet thrust data at only Mach 4 as a function of altitude. The model that tracks this data very closely is a fairly simple exponential fit:

(M 4 only) Fnj / Fnj at 5 kft = 1.00 exp [-.034(h - 5 kft)^1.02]

The scaling value that converts these ratios to actual thrust is net jet thrust of a 1 square foot-size engine (based on outside diameter) at Mach 4, 5000 feet conditions. This is essentially the frontal thrust density Fnj/So = 4860.3 lb/sq.ft.

This particular engine has a translating-spike inlet for constant shock-on-lip operation at all flight Mach numbers from 1.5 to 6. Therefore, it has no additive (pre-entry) drag. The engine is sized so that it does not spill air sub-critically in this flight envelope (except a tiny amount at low speeds and very high altitudes). So, installed thrust and impulse are pretty much the same values as net jet.

The engine specific impulse data are harder to correlate, since the variation with altitude does not diminish to insignificance, the way it did with normalized thrust ratios. Still, all the curves have the same shapes vs flight Mach number or vs altitude. Two plots are given: one of specific impulse vs Mach parametric upon flight altitude, the other specific impulse vs flight altitude parametric upon flight Mach number. For BOE rough-sizing purposes, the second plot may be easier to use as a graphical estimating tool.

Once again, the impulse data are actually for net jet thrust-drag accounting. But, for this particular design, the installed numbers are the same.


Tuesday, July 20, 2010


On ramjet data postings:

I am working on a back-of-the-envelope set of methods to get "in the ballpark" with rocket and ramjet vehicle designs, including parallel-burn designs where both types of engine burn simultaneously. This would include both fast ascent non-lifting ballistic trajectories, and lifting-vehicle trajectories at far more modest climb angles. These are entirely different analyses from any practical standpoint. This work is still in progress, and is aimed at rough-sizing configurations that could be refined later with a real trajectory computer program model.

On the Gulf oil spill:

I stand by my two earlier posts. Although I see little or no movement toward changing the rules for deep-water drilling, I think my four suggestions, if implemented, would have prevented the current disaster. I see no need to stand down deepwater drilling for 6 months or any other extended period of time. I see a need to change the rules quickly, and that should not take more than a week or two. Don't reinvent the wheel, just use what I posted. They are:

1. eliminate the liability caps and statutes of limitations; faced with true costs, safety and preparedness will receive proper attention
2. use a double blowout preventer for the increase of reliability due to redundancy, like the Europeans do in the North Sea
3. drill the relief wells while drilling the main well, so it could be relieved (if need be) within days not weeks-to-months
4. spend some federal R&D monies on better booms, better skimmers, better absorbents, and even-better bioremediation products.

To that list I would add spend some money on developing the oil-water separation techniques so that fresh oil making a free ascent to the surface could be used.

The second post said use bioremediation in addition to the other remediation methods (booms, skimmers, absorbents). Where dispersants interfere with bioremediation or the other methods, quit using dispersants. Nothing works if you drive the oil down deep in the water as microscopic globules. Hiding the problem instead of addressing it is utterly stupid.

The federal EPA is going to have to take its blinders off regarding bioremediation. They (and many academics) seem to think that bioremediation is a new thing to be studied to death. It is not; it was used successfully in a Galveston Bay spill 20 years ago, including both on-the-water and in-the-marshlands oil. It works, we already know that, here in Texas.

How come no one else seems to be doing it? The bioremediation products are already available commercially. This is not R&D, this stuff is available for sale, now.

On global warming:

Now that El Nino is over, and the heat has returned with a vengeance, I noticed that my global warming-skeptic friends have grown strangely quiet. I don't care whether humans caused the warming or not, the real question is what do we do about it, considering the devastating effects of massive sea level rise, among other consequences.

Latest science journal estimates put the expected sea level rise at 0.3 to 1.8 meters by 2100 AD. (The trend of these estimates over the last few years has been sharply upward, by the way.) Almost a billion people live within a meter or two of current sea level. That's a big, permanent refugee migration across international borders, when this civilization demonstrably cannot handle the temporary evacuation of one city (New Orleans), within one nation's borders.

The prudent thing is to plan how to cope with this disaster, and to try to mitigate the warming somewhat, to buy some extra time for that "coping".

On the North Korean sinking of the South Korean ship:

I see no reason to change my stance, which was to blockade the North Korean navy into its ports. They were a problem on the high seas, well, don't let 'em out there any more. Simple. Direct.

As for how the North Korean government has been behaving, we should use this incident to our advantage. Rub their noses in it, with no wiggle room to save face. If we do not do that, then they will think they "won", and their behavior will never change.

On a recent birthday surprise:

My wife took me to East Texas to ride the steam train (Texas State Railroad, Rusk to Palestine and back). The real surprise was that she bought me the "locomotive cab rider" ticket. I rode in the locomotive with the driver and the fireman, and I learned how to do what they did, by watching what they did, how they did it, what they did it with, and talking with them. The locomotive was a 109-year-old A.L. Cooke 4-6-0 woodburner, that had been long ago converted to fuel oil. Depending on power levels being generated, it was 110 to 140 F in that cab. I now understand why the old time steam crews always hung out the windows: it was to stay cooler in the breeze. I had a blast!!!!!!! Thank you, my dear! Wonderful present.

On a recent trip to California:

I went to Mojave to visit a small private rocket company at the airport. This was the first time in 25 years I had been there. Mojave was about the same as I remembered. "LA sprawl" has spilled through the mountains and engulfed Palmdale and Lancaster, though. There were more buildings and businesses on the airport, and the mix of aircraft in the "boneyard" has changed.

The little rocket company was very impressive, and was interested in someday applying a technology with which I had extensive and direct experience years ago in the defense industry: ramjet propulsion. They had been looking for someone without success, when they ran across me. Apparently, I am one of very few surviving American engineers with that kind of all-around ramjet expertise and experience. It was a bit of a shock to realize that I apparently outlived nearly all of them.

Alternate fuel work:

I recently began some tests in the old ethanol VW before I re-mothball it. I reworked its carburetor with a main jet adjusting needle, and reset everything to run straight gasoline. Then, I started testing stiffer and stiffer ethanol blends in an otherwise-gasoline car. There are some driveability issues in carburetion that don't show up with fuel injection, but I was looking for the reduced intake vacuum that indicates a late timing problem. So far, I have reached an E-50 blend with this vehicle, and I have not yet seen the timing problem.

In the F-150, I saw this late timing effect at an E-47 blend. In the Nissan, I got a little past E-50 by accident, and I believe I saw the problem. (Those two are fuel injected.)

For the next VW test, I plan to evaluate timing at E-53.

All the lawnmowers, the F-150, and the Nissan are working just fine on E-25 to E-40 blends, pretty much year round. All of these are "factory stock". Their engines are cleaner than "normal" inside, and at least the truck's tailpipe is "bare steel" clean.

To have the EPA balk on raising the gasohol cap from E-10 to E-15 is utterly ridiculous stupidity on their part, or egregious corruption due to lobby monies, or both. (Probably both, in my opinion.) Brazil has used E-20 to E-25 gasohols for decades, and I am not the only investigator to suggest that E-30 to E-35 will be "just fine".

Sunday, July 11, 2010

More Ramjet Performance Numbers for the Strap-On Pod

The image is a graph of overall energy conversion efficiency for the ramjet strap-on pod, for which cycle analysis performance was posted in 4 articles previously. 3 of these were dated 2-20-10, and the 4th was dated 2-28-10.

The energy conversion efficiency relates engine thrust power delivered to the airframe, to the fuel combustion energy flowing from tank storage. It is a sort of overall energy efficiency, not a cycle efficiency. The thrust power is engine thrust times flight velocity in appropriate units of measurement. The energy flowing from storage is the engine fuel mass flow, times the fuel gravimetric lower heating value, again in appropriate units. Efficiency is the ratio of thrust power to energy flow from storage.

The thrust can be reported in either of two force accounting schemes, net jet or installed. These differ primarily in whether the inlet additive (pre-entry) drag is subtracted from thrust (installed) or added to airframe drag (net jet). This particular translating-spike inlet, which maintains shock-on-lip operation at all flight Mach numbers, has no additive drag. So, in this particular case, there is no difference.

In the ratio creating the efficiency, thrust divides by fuel flow to create the ramjet engine's specific impulse. Again, normally there would be two different values, net jet and installed. But, in this particular design, there is no difference.

The ratio equation looks like this:

efficiency = (ramjet Isp)(flight velocity)/(gravimetric fuel lower heating value)

In the graph above, there is very little effect of altitude, from 5000 feet all the way to 100,000 feet. The variation with flight Mach number is almost parabolic, if one fairs through the middle of the altitudes. A parabolic model was formulated and included in the graph. That model equation is:

efficiency = -0.22(M - 4.2)^2 + 0.33

Remarkably enough, if one does not spend much time flying at speeds below about Mach 2, a simple constant average figure of 30% efficient would be a good representation for purposes of very crude back-of-the-envelope models based on energy quantities.

Calculation of these quantities is very easy to include in the cycle analysis for the ramjet engine, as the above thrust power efficiency equation indicates. Whether this has utility beyond crude back-of-the-envelope calculations remains to be seen. But, it is very intriguing.