Why aren't pulse jets used in modern designs?

[LaughingCheese]

What are the limitations of pulse jets that make them unsuitable for modern jet aircraft?

You don't see pulse jets on any jet aircraft. Do they not produce enough thrust? They can't scale well?

It's a shame because they seem so simple compared to a modern jet engine. Or is the simplicity its downfall?

[Graham Kennedy]

No compressors, and so low pressure and hence low specific impulse - meaning not a lot of thrust generated per unit of fuel burned.

[McAvoy]

Alot of stuff. Most aircraft is already tight on space and weight and from what I have heard you still need jet engines because pulse jets while lightweight, are not that great in high end performance.

[IanKennedy]

I think they're pretty noisy too.