Abstract: An air intake includes a spike and a cylindrical cowl. The spike is composed of a plurality of plates which are arranged axial symmetrically around a central axis thereof, and the cowl includes an inner wall parallel to the central axis and is formed so as to enclose a rear portion of the spike via a given space. The adjacent ones of the plates form respective aerodynamic compressive surfaces in spaces formed by the adjacent ones. The distances between the adjacent ones of the plates are variable, and the distance between the forefront of the spike along the central axis and the cowl is variable.

Abstract: It is an object of the present invention to provide a flying object using a thin elongated nose cone with a small tip angle for reducing the air resistance during flying, wherein the maximum loading capacity can be increased without decreasing the volume efficiency of the flying object by limitations placed on the accommodation space, regardless of the structure thereof. In the flying object in accordance with the present invention, which comprises a nose cone in the tip portion, the nose cone portion has a compressed structure in the axial direction during accommodation and expands on the tip side in the axial direction during flying, due to an expandable nose cone structure such that a disk with a small diameter is disposed in the forward position and the disks with a successively increasing diameter are disposed in the axial direction.

Abstract: It is an object of the present invention to provide a flying object using a thin elongated nose cone with a small tip angle for reducing the air resistance during flying, wherein the maximum loading capacity can be increased without decreasing the volume efficiency of the flying object by limitations placed on the accommodation space, regardless of the structure thereof. In the flying object in accordance with the present invention, which comprises a nose cone in the tip portion, the nose cone portion has a compressed structure in the axial direction during accommodation and expands on the tip side in the axial direction during flying, due to an expandable nose cone structure such that a disk with a small diameter is disposed in the forward position and the disks with a successively increasing diameter are disposed in the axial direction.

Abstract: An air intake includes a spike and a cylindrical cowl. The spike is composed of a plurality of plates which are arranged axial symmetrically around a central axis thereof, and the cowl includes an inner wall parallel to the central axis and is formed so as to enclose a rear portion of the spike via a given space. The adjacent ones of the plates form respective aerodynamic compressive surfaces in spaces formed by the adjacent ones. The distances between the adjacent ones of the plates are variable, and the distance between the forefront of the spike along the central axis and the cowl is variable.

Abstract: The present invention provides a method for preventing the decrease of the efficiency of heat transfer, caused by frost formation, in a precooler of an air breathing engine. In the precooler, the heat exchanger tube is provided. Into the heat exchanger tube, liquid hydrogen serving as a coolant is supplied. The main air flow is sent to the precooler via the intake duct, and the main air flow which is cooled down there, is then sent to a compressor of the air breathing engine. Via the nozzle provided in the middle of the intake duct, ethanol is mixed into the main air flow. Ethanol is carried into the precooler, and condenses together with the water vapor on the surface of the heat exchanger tube. A frost layer thus formed has less cavities and low thermal resistance as compared to that formed when the water vapor condenses solely. Therefore, the decrease of the performance of the heat exchanger, which is caused by the frost formation, can be prevented.

Abstract: A liquid oxidizer immersion hybrid rocket having a combustion chamber, a porous fuel material placed in the combustion chamber, a liquid oxidizer filled into pores of the porous fuel material, and two holding plates provided in the combustion chamber so as to hold opposite ends of the porous fuel material respectively. The porous fuel material comprises a large number of layers stacked one another in an axial direction of the combustion chamber.

Abstract: A heater for use with a Stirling engine and a method for heating a working fluid for a Stirling engine is disclosed. The heater has a burner, heater tubes disposed in the burner, a space formed around the heater tubes which is filled with heat-storing material, and a high-temperature heat source. The heat-storing material is sealed by a seal member. Heat produced by the high-temperature heat source is supplied to the heater tubes via the heat-storing material; hence the heat-storing material acts as a secondary heat source. Heat is stored in the heat-storing material in the form of sensible heat or latent heat, or a chemical reaction is employed.