Cover of: Studies to increase the flow rate of military jet fuel by reducing frictional drag | Richard B. Nygaard

Studies to increase the flow rate of military jet fuel by reducing frictional drag

  • 0.15 MB
  • English
University of Kansas , Lawrence, Kansas
Aeronautics, Chem
ID Numbers
Open LibraryOL25200406M

Studies to increase the flow rate of military jet fuel by reducing frictional drag. By Richard B. Nygaard. Get PDF (7 MB) Abstract. This thesis document was issued under the authority of another institution, not NPS.

At the time it was written, a copy was added to Author: Richard B. Nygaard. Reducing Aerodynamic Drag and Fuel Consumption Year statistics for combination trucks (tractor-trailers) on nation’s highways * million trucks registered billion miles on nation’s highways, % increase/yr billion gallons diesel fuel consumed, % increase/yr mpg, or gallons/ miles ~ million barrels/day **File Size: 2MB.

Description Studies to increase the flow rate of military jet fuel by reducing frictional drag EPUB

From the fuel to air ratio, we can obtain the fuel mass flow rate by a simple multiplication. f = [(Tt4 / Tt3) - 1] / [(nb * Q) / (cp * Tt3) - Tt4 / Tt3] mdot f = f * mdot a The engine air flow rate is normally set by conditions in the nozzle.

We can use the value of fuel to air ratio to determine the engine's specific fuel. Frictional drag is a significant part of the overall resistance, and ship operators have known for years that a smooth hull free of "fouling" will lead to higher ship speeds and fuel savings.

A much larger reduction in the frictional drag can be achieved if the water is moved away from the surface entirely. Fuel flow for a jet at % rpm at altitude compared to that at sea level is less a pilot is flying an airplane at the speed for best range under no wind conditions.

Reducing fuel consumption is a way to manage the risk related to fuel price fluctuations and uncertainty surrounding a future environmental policy. Injet fuel prices reached levels more than three times those of While fuel prices fell from their highs, the spike.

The variable head flow meters, such as the venturi tube, flow nozzle, orifice meter, and the equations for calculating the velocities and flow rate from the pressure drop, are explained. The importance of the discharge coefficient and how it varies with the Reynolds number and the beta ratio are also discussed.

Multiple parameters have a role in this, but high altitudes are not the best operating conditions in general for an engine: see hot and high tests, but are the best for an aircraft!.

High altitude means - less thrust because of lower air density - less power in the gas generator due to less oxygen density - far less losses from air resistance to the fuselage.

Publisher Summary. This chapter describes the flow of a steady one-dimensional stream of gas through a duct (circular tube). A set of equations are used for preliminary design to measure the changes in combustor cross-sectional area, variations in gas molecular weight and specific heat, exchange of heat with surroundings, drag caused by solid particles in the flow, and loss due to friction in.

This requires greater thrust to balance the drag, which increases the fuel flow and reduces the endurance. Air density (altitude) Increasing altitude (decreasing air density) increases the endurance due to the increase in jet engine efficiency.

However, at a very high altitude, compressibility will increase the drag, causing increased fuel flow. The race for speed ruled the early Jet Age on aviation. Aircraft manufacturers chased faster and faster planes in a fight for pride and capability. In the early s, dreams were that the future would be supersonic, but fuel economy and unacceptable noise levels made that era never happen.

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After the oil crisis, the paradigm changed. The average cruise speed on newly developed aircraft. This book is great for modelers in general, model-kit collectors, and drag-racing fans young and old alike.

It covers the options, collectability, variety, availability, and value of these wonderful kits, and then concentrates on the highly detailed drag racing-only kits that became available starting in. An axial compressor is a gas compressor that can continuously pressurize is a rotating, airfoil-based compressor in which the gas or working fluid principally flows parallel to the axis of rotation, or differs from other rotating compressors such as centrifugal compressor, axi-centrifugal compressors and mixed-flow compressors where the fluid flow will include a "radial.

Therefore, the flow is turbulent. For cast iron, ε= × 10−4 ft. Therefore, the relative roughness is () () 4 10 10 3 ft D ft ε − =× = ×− Because we have the values of both the Reynolds number and the relative roughness, it is efficient to use the Zigrang-Sylvester equation for a.

Col. Linda Hurry applies the Jet A1 fuel sticker on an R11 refueler as part of the conversion from JP8 fuel to Jet A1 fuel Oct. 15,Scott Air Force Base, Ill. Jet A1 fuel was created as a cost savings measure by the Department of Defense and.

Federal Aviation Administration. Air mass vs fuel mass. For a fuel consumption of 22% of the T/O consumption, it can be assumed relatively safely that the air flow is in proportion, so we can roughly estimate air mass flow in cruise to be about * = kg/s. This is supported by figures found online in non authoritative sources, like page of this book.

Drag is the force that a moving body feels when the flow of air around it starts to become turbulent. If you ride a bike or you've ever run a sprint race, it'll be very obvious to you that drag increases with speed.

But a very important point is that it doesn't increase linearly as your speed increases but according to the square of your speed. Explain the term Stokes flow and term inal velocity. Show that a spherical particle with Stoke s flow has a term inal velocity given by u = d 2g(U s - U f)/18 P Go on to show that C D =24/R e c.

For spherical particles, a useful em pirical formula relating the drag coe fficient and the Reynold s num ber is 1 R 6 R 24 C e e D Given U. at what speed with reference to L/D max does maximum rate of climb for a jet airplane occur. Shock induced separation or air flow occurring symmetrically near the wing root in an airplane is hazardous because.

a bank angle of 30 degrees will increase induced drag by. 33 percent. swept wings. The minimum drag for a jet airplane does not vary with altitude. True. Figure shows an increase in specific range with altitude because: Fuel flow remains about the same while airspeed increases.

A jet airplane is flying to obtain maximum specific range. As fuel is burned the pilot must. Note that mass flow is the sizing parameter: doubling the airflow, doubles the thrust and the fuel flow.

However, the specific fuel consumption (fuel flow/net thrust) is unaffected, assuming scale effects are neglected.

Similar design point calculations can be done for other types of jet engine e.g. turbofan, turboprop, ramjet, etc. A: Engineers reduce friction drag by making the airplane more streamlined, the wings narrower, or by using new materials that make the surface more smooth, decreasing the ability for the force of drag to effect it.

As the roughness and surface area of the airplane decreases the friction drag will decrease. Generally, pressure drag is more of a concern than friction drag.

And since power is related to air mass flow per minute, you can expect a power increase of roughly 2 percent from inlet cooling. That’s an additional 10 to 12 hp on a hp engine. Again, it is difficult to quantify all of this without accurate data logging to compare against track performance, which would most easily be seen as increased.

This chapter summarizes the findings on potential neurotoxicity from exposure to jet-propulsion fuel 8 (JP-8) presented in the National Research Council report Permissible Exposure Levels for Selected Military Fuel Vapors (NRC ) and reviews additional studies, most of which were completed after the report was published.

Since the report was released, additional epidemiologic. From conservation of momentum we know that the thrust of a jet engine is governed by the mass flow rate, and the difference between the entry and exit velocities of air into, and out of, the jet engine.

For a fixed airspeed, this means that the level of thrust depends on both the exit jet velocity of the gases and the mass of air flowing through the engine per second. is a platform for academics to share research papers.

Within the United States, the military uses diesel fuel extensively in ground. equipment and in many tracked and wheeled vehicles.

JP-8 is the fuel used commonly in fixed-wing and rotary-wing aircraft and as an alternative in vehicles that routinely use diesel. The navy uses JP-5 as the fuel.

Details Studies to increase the flow rate of military jet fuel by reducing frictional drag EPUB

The study has drawn our attention to the following observations: (1) the Savitsky method of prediction is valid only in the planing speed range of the hull forms where the wetted keel length is.

The velocity out of a free jet can be expressed as. v 2 = (2 (p 1 - p 2) / ρ) 1/2 (1). where. v 2 = velocity out of the jet (m/s). p 1 = pressure before the jet (N/m 2, Pa).

p 2 = ambient pressure after the jet (N/m 2, Pa). ρ = density of the fluid (kg/m 3). Note. - the density ρ is constant in incompressible flows and the equations are valid for liquids (like water) but not for gases. If the TSFC were the same () for the two engines, in order to increase thrust, we would have to increase the fuel flow rate by an equivalent amount.

For example, Initial thrust = pounds Thrust with afterburner = pounds TSFC = Fuel flow rate = pounds per hour. But a turbojet with an afterburner has a typical TSFC value of C. Fuel Flow Model BADA provides fuel flow models for nominal and idle-thrust conditions.

The expression for nominal fuel flow for jet aircraft is given as a function of true airspeed and thrust: f nom=C f11+ V C f2 ⎛ ⎝ ⎜ ⎞ ⎠ ⎟ ⋅T (10) Minimum fuel flow for idle-thrust is: f .The principle aim of the present investigation was to determine the modification in flow and heat transfer behavior caused by the presence of the antimisting polymer additive in jet fuel.

The present study indicates that the AMK skin friction versus Reynolds number, or Nusselt number versus Reynolds number behavior, can be divided into threemore».