Help with my design

[Hagar]

I'm not an engine man but from what I know of engine cooling the ratio between the size of the air intake & the rear opening is critical. This might be even more critical with a low-speed pusher as there is no airflow from the prop over the engine for cooling while stationary or at low airspeeds. The shape of the intake is also important. This is a subject in its own right.

On our R/C models we make sure that the capacity of the rear outlet is larger than the front intake to ensure an efficient airflow. On close-cowled engines the cylinders themselves are usually left exposed.

[mobius1]

I understand what you are getting at. I will make the necessary adjustments to the engine shell today.

About the confusion over the seat set-up and windshield. I had a discussion about this issue with others in the past.

There is important reasoning behind why the windshield is 2 parts with reinforcement down the middle. In the unlikely but possible event that a projectile was to hit the windshield (lets take a bird for example), the collision would drive the glass in-wards towards the pilot. Naturally this could cause serious to fatal injuries.

If however the windshield is 2 parts with reinforcement down the middle, it is more likely that the glass would smash and head left or right, depending on which window it is. The reinforcement would alter the glass's direction on impact and therefore providing a possible shield for the pilots head and chest.

Its not 100% chance of survival but it does provide enough safety to class as a priority.

The same would apply in an emergency or heavy landing. During the impact, that reinforcement could help oppose the inward crushing action as well as parrying the glass elsewhere.

This is very much open to discussion though and I always appreciate the oppinions of others.

Noel

[Hagar]

On the point of the windscreen I would have to disagree. I'm not sure a bird strike would be too serious at the speeds we're talking about. An unobstructed direct forward view for the pilot is far more important. IMHO

If you look at any modern ultralight or homebuilt the windscreen is invariably a one-piece moulding. Accurate one-piece moulded "Perspex" canopies & windscreens were pioneered by companies such as Miles Aircraft on types like the Messenger back in the early 1940s & have been used successfully on light aircraft ever since.



I've never heard of one shattering due to a bird strike, even on comparatively high performance types like the Burt Rutan canards.

[mobius1]

I worked on the engine shell some more. It now includes a grill feature at the front and numerous exit ducts located at the rear and sides)



Whats the general oppinion of this new adjustment?

[Hagar]

This is more like I imagined it. Now it has 2 seats you could retain the central pillar if you wish. That pod looks a tad frail without it to me. This way you can go back to the idea of the gull-wing doors.

[mobius1]

Ive been observing the progress on the cockpit. to my dispair - it appears that there is room for not 2 seats, not 4 seats but 6 seats. Ive been testing it out and its true. I really dont know what im going to do about that

[Hagar]

LOL This is the first time I've heard an aircraft designer complain about too much space.

Surely it all depends on the scale. If you reduce it the available space is reduced accordingly. At the risk of messing up the cute look of your little aircraft you could change the cross section of the nose to a cylindrical shape more like the Streak Shadow in my photo. Then you can make the rest of the pod narrower & use a similar tandem seating arrangement. You still need to find room for a fuel tank & baggage space is always handy. I think it's worth a try. Keep what you've already done as a possible future development, maybe with 2 engines.

[mobius1]

I think I have solved the issue without much need for adjustments. What I was quick to forget, was the fact that the rear part of the cockpit needs to hold some reinforcement work for the shaft (connects the cockpit to the rear of the aircraft). There will also be a requirement for batteries, cables, possibly fuel tank, possibly emergency fuel tank. Other possibilities will be some storage space for the crew, life jackets, and other safety equipment