Abstract: A jet engine has an inlet 11 configured to introduce air, and a combustor 12 having a fuel injection port 30a that injects a fuel, and configured to combust the fuel injected from the fuel injection port 30a by using the air. The combustor 12 has a separation section 14 defining the air passage FA through which the air flows, between a rear end 15 of the inlet and the fuel injection port 30a. A plurality of turbulent flow generating sections (20;25) are arranged in the separation section 14 to makes the air flow turbulent. Each of the plurality of turbulent flow generating sections (20;25) contains a member (21;22;25B) which can restrain the turbulence of the air flow by moving or disappearing. It can be prevented that a high-pressure region reaches the inlet so that the thrust of the jet engine is reduced.

Abstract: A scramjet engine has a first passage forming member and a second passage forming member. A passage is formed between a first surface and a second surface. The passage has an upstream zone, a combustion zone and a downstream zone. A cavity of a concave shape is provided on the first surface in the combustion zone. The first passage forming member has a convex section located in the upstream zone, a first fuel injection section configured to inject fuel into the passage from a first fuel nozzle provided for the convex section, and a second fuel injection section configured to inject fuel to the cavity. The second passage forming member has a third fuel injection section configured to inject fuel to a direction toward the first surface from the second surface in the passage through a second fuel nozzle provided in the downstream zone.

Abstract: A scramjet engine has first and second passage forming members. A passage is formed between the first surface and the second surface. The passage has an upstream zone, a combustion zone and a downstream zone. A cavity of a concave shape is provided on the first surface in the combustion zone. The first passage forming member has a convex section located in the upstream zone, a first fuel injection section which injects the fuel into the passage from a fuel nozzle provided for the convex section, and a second fuel injection section which injects the fuel to the cavity. The second passage forming member has a third fuel injection section which injects the fuel to a direction toward the first surface from the second surface in the passage through the second fuel nozzle provided in the downstream zone.

Abstract: A joined structure includes a joint section in which a plurality of tubular bodies formed of a ceramic-based composite material are joined to each other such that end surfaces of the tubular bodies abut each other via an intermediate material. The joint section is configured such that each of the end surfaces of the joined tubular bodies is inclined from one of an inner surface and an outer surface of the tubular body toward the other.

Abstract: A jet engine has an inlet 11 configured to introduce air, and a combustor 12 having a fuel injection port 30a that injects a fuel, and configured to combust the fuel injected from the fuel injection port 30a by using the air. The combustor 12 has a separation section 14 defining the air passage FA through which the air flows, between a rear end 15 of the inlet and the fuel injection port 30a. A plurality of turbulent flow generating sections (20;25) are arranged in the separation section 14 to makes the air flow turbulent. Each of the plurality of turbulent flow generating sections (20;25) contains a member (21;22;25B) which can restrain the turbulence of the air flow by moving or disappearing. It can be prevented that a high-pressure region reaches the inlet so that the thrust of the jet engine is reduced.

Abstract: A jet engine has an inlet, and a combustor with a fuel injection opening. The combustor has wall sections that define an air flow path. The wall section has a ramp section with a ramped surface and a first wall surface extending from an end of the ramped surface on the front side. The fuel injection opening is arranged in the ramp section. A ramped angle ? of the ramped surface to the first wall surface is equal to or more than 13.5 degrees. The height of the ramp section protruding from the first wall surface is equal to or less than ? of the height of the entrance of combustor. In this way, the ramp angle of the ramped surface of the ramp section is made large to promote mixing of fuel and air, and flame stabilization behind the ramp section is made possible.