Random Aerodynamic Oddity of the Day Thread

[cRiPpLe_rOoStEr]

Originally Posted by slowmover

In the late 70’s and early 80’s saw development of wheeled Army land vehicle engines that were multi-fuel. Could be moved from one theater to another more easily. Could use that theaters less desirable fuel. Chicken & Egg problem. These were modified diesels.

I'm aware of multifuel engines in the Deuce and a Half. The only other multifuel engines I'm aware are those Elko Multifuel, meant for light-duty vehicles and which were tested even in Brazil in the '80s and early '90s. I recently had a talk about the Elko Multifuel engine with an Argentinian who owns a VW Transporter T4 with the IDI 2.4L 5-cyl Diesel, and it got me thinking about how those older hot-bulb engines widely used for agricultural machinery and stationary devices were nearly unbeatable as a multifuel engine, even though the pre-chambers in a (relatively) modern IDI bore some resemblance to the vaporizing bulb of the hot-bulb engines.

Back on topic: considering how smaller a modern diesel rated at a given power is compared to what was available some 20 years ago, and the smaller packaging enabling the fitment on vehicles with a smaller frontal area, there might be some aerodynamic benefit to be accounted...

[freebeard]

https://cdn11.bigcommerce.com/s-6siy...=2?imbypass=on

I saw one of these on the street today (yesterday? Already?) and from a distance it looked like a means of creating a box cavity on the back of a Camry without compromising the tail lights.

In this picture it looks more like a body crease inlay than a raised separation edge.

[kach22i]

Buick "Safari"
https://www.cherokeeforum.com/f46/ec...241367/index3/

[kach22i]

Ljungstrom Internal Propulsion Aeroplane Projects - "Jet" Aircraft from 1928! - Luftwaffe and Allied Air Forces Discussion Forum

Olof Ljungstrom, an engineer in the aircraft division of the Ford Motor Company, developed a propulsion system featuring boundary layer removal by means of a piston engine driving an axial flow turbine blower inside the aircraft. In 1928, he proposed a giant seaplane and the small monoplane pictured above, both of which were powered with this system. The accompanying image gallery reproduces the proposal documents, correspondence with NACA, and several photos and drawings of these futuristic though flawed machines.

30ish images..............

Ljungstrom Internal Propulsion Aircraft Projects (1928)
https://retromechanix.com/ljungstrom...projects-1928/

In 1928, Olof Ljungstrom of Detroit, Michigan submitted a pair of unusual aircraft proposals to NACA which featured boundary layer removal via a primitive form of jet engine, in which a piston engine drove an axial flow turbine blower inside the aircraft. The power plant is reminiscent of that used by the Caproni Campini N.1, which first flew August 27, 1940. However, the Ljungstrom design did not feature a combustion chamber and was less advanced than the N.1, which was not a true jet itself but a “motorjet” or ducted fan type. Ljungstrom appears to have been employed as an engineer in the aircraft division of the Ford Motor Company, as W.B. Mayo, the head of this organization, sent the proposals to Edward P. Warner, Assistant Secretary of the Navy for Aeronautics, on Ljungstrom’s behalf.

EDIT:
https://retromechanix.com/ljungstrom...age/image-1704

[freebeard]

Reminds me of the Shauberger Trout Turbine as a half-body.

On 2nd thought it the reverse. Schauberger had the intake at the front and the outlet at max camber.

[kach22i]

Reminds me of blower flaps or certain experimental short take off craft.

I'm not remembering the leading edge design names at the moment, but there is the below.


https://en.wikipedia.org/wiki/Blown_flap

Blown flaps, or jet flaps, are powered aerodynamic high-lift devices used on the wings of certain aircraft to improve their low-speed flight characteristics. They use air blown through nozzles to shape the airflow over the rear edge of the wing, directing the flow downward to increase the lift coefficient. There are a variety of methods to achieve this airflow, most of which use jet exhaust or high-pressure air bled off of a jet engine's compressor and then redirected to follow the line of trailing-edge flaps.

Internal blown flaps were used on some carrier and land-based fast jets in the 1960s, including the Lockheed F-104, Blackburn Buccaneer and certain versions of the Mikoyan-Gurevich MiG-21.........

A Buccaneer pictured with the blowing slots visible on the leading edges. The extended flaps are contributing to the coanda airflow over the wing.

Not the one I was thinking of, but interesting.

Olof Ljungstrom seems to have intended the drawing/sucking force of the aft fan to cause flow over the wing, more akin to the Channel/Custer wing I suspect.

Channel wing
https://en.wikipedia.org/wiki/Channel_wing

Custer's summary of his invention was that the key to the lift created by a wing is the velocity of the stream of air passing over the wing, not the velocity of the airplane itself: It's the speed of air, not the airspeed!

Sucks, doesn't blow.


https://www.researchgate.net/figure/...fig4_308028083

Velocity distribution around the top of a suction channel wing due to the suction Coanda effect

[kach22i]

https://www.researchgate.net/figure/..._fig7_51216017

Images courtesy of E. Paterson.

PDF download paper
https://www.google.com/url?sa=i&rct=...71668952822899




From the above 2012 paper:

Characterization and Design of Tubercle Leading-Edge Wings

Mark W. Lohry, David Clifton and Luigi Martinelli Corresponding author: mlohry@princeton.edu

Department of Mechanical and Aerospace Engineering Princeton University, Princeton, NJ 08544, USA

[kach22i]

PDF Download - Over the wing propellers
https://www.google.com/url?sa=i&rct=...71668952822899


onera ampere
onera ampere - Sustainable Skies

Ansell's team's research might lead to aircraft such as the French ONERA Ampere

Battery technology is opening up a whole new world in some design fields.

[kach22i]

The little bite taken out of the front wing explained.

https://racer.com/2019/01/18/indycar...t-wing-tweaks/

“We did some testing with IndyCar late last year and tried this change,” Simmons added. “IndyCar did some CFD work to find why it wasn’t easy to follow other cars, and one of the studies found the air separated at the edge of the wing next to the end plate, where it stalls, and the solution they came up with was to shorten the chord at the ends of the wing by cutting out the notches, which reduces the stall, cleans up the air and makes the front wing more efficient and consistent for the drivers in traffic.”

IndyCar reveals speedway front wing tweaks
https://racer.com/2019/01/18/indycar...t-wing-tweaks/

[kach22i]

Perhaps someone wants to take a risk and elaborate on how this central spline works, and what it is most similar to.

IndyCar to test aeroscreen at IMS on Wednesday
By: Marshall Pruett | October 1, 2019
https://racer.com/2019/10/01/indycar...morrow-at-ims/

.........to test visibility through the PPG-supplied material, and to provide feedback on any buffeting, chassis handling, cockpit temperatures, helmet lift, and a variety of other items on the series’ checklist................

...........gather chassis data and driver input on how lapping in turbulent air affects chassis stability, aerodynamic stability, cockpit airflow, etc................

“The 3D-printed titanium upper frame piece from Pankl itself is a work of art.

Of the new features present, a central spine is shown on the leading edge of the aeroscreen. The carbon-fiber piece, which aligns with the central spine on the nose and damper cover on the Dallara DW12 chassis, assists in stability when a driver is at a high degree of yaw..................

While there, Frye said Dale Coyne Racing’s Sebastien Bourdais, who is one of a handful of IndyCar drivers who wears glasses, will turn laps using the aeroscreen. The Frenchman is expected to report on the experience of driving while using prescription glasses, a visor, and the heavily curved aeroscreen, and offer any insights on whether the trio of items placed in front of his eyes provide any problems.