Method and means for controlling the air pressure in a sound-proofed hangar for testing jet engines

An exhaust gas silencer for conducting the exhaust gas jet of a jet engine out of a sound-proofed hangar serving to test jet engines into the atmosphere, characterized in that screens are provided on the silencer for varying the flow resistance or the free flow cross-section of the area difference between the inlet cross-section of the exhaust gas silencer and the exhaust jet cross-section, wherein said screens have different diameters at the axially opposite openings thereof with the smaller diameter being located closer to the thrust pipe opening of the jet engine.

A method of controlling the air pressure in a sound-proofed hangar in which jet engines are tested, comprising the steps of conducting the exhaust gas jet of at least one jet engine through an exhaust gas silencer out of the hangar into the atmosphere, sucking an amount of cooling air into the exhaust gas silencer by the injection action of the exhaust gas jet, and adjusting said amount of cooling air by varying the flow resistance or the free flow cross-section of the area difference between the inlet cross-section of the exhaust gas silencer and the exhaust jet cross-section by means of screens of a predetermined flow resistance having the form of a truncated cone with the smaller opening facing the thrust pipe opening of the jet engine and being releasably connected with the exhaust gas silencer so that the air pressure in the hangar does not drop below a predetermined value.

A method of controlling the air pressure in a sound-proofed hangar in which jet engines are tested comprising the steps of conducting the exhaust gas jet of at least one jet engine through an exhaust gas silencer out of the hangar and into the atmosphere, sucking an amount of cooling air into the exhaust gas silencer by the injection action of the exhaust gas jet, and adjusting said amount of cooling air by varying the flow resistance or the free flow cross-section of the area difference between the inlet cross-section of the exhaust gas silencer and the exhaust jet cross-section by means of a set of interchangeable screens having the form of a truncated cone with different flow resistances arranged adjacent to the inlet opening of the exhaust gas silencer so as to surround the exhaust gas jet concentrically with the smaller opening facing the thrust pipe opening of the jet engine and being releasably connected with the exhaust gas silencer so that the air pressure in the hangar does not drop below a predetermined value.

A method of controlling the air pressure in a sound-proofed hangar in which jet engines are tested comprising the steps of conducting the exhaust gas jet of at least one jet engine through an exhaust gas silencer out of the hangar and into the atmosphere, sucking an amount of cooling air into the exhaust gas silencer by the injection action of the exhaust gas jet, and adjusting the amount of cooling air by varying the flow resistance or the free flow cross-section of the area difference between the inlet cross-section of the exhaust gas silencer and the exhaust jet cross-section by means of screens arranged adjacent to the inlet opening of the exhaust gas silencer so as to surround the exhaust gas jet concentrically with the smaller opening thereof facing the thrust pipe opening of the jet engine, the screens having at least two mutually displaceable conical ring portions releasably connected with the exhaust gas silencer and connected together by connection bolts guided in slots, wherein the air pressure in the hangar does not drop below a predetermined value.

A method of controlling the air pressure in a sound-proofed hangar in which jet engines are tested, comprising the steps of conducting the exhaust gas jet of at least one jet engine through an exhaust gas silencer out of the hangar and into the atmosphere, sucking an amount of cooling air into the exhaust gas silencer by the injection acting of the exhaust gas jet, adjusting the amount of cooling air by varying the flow resistance or the free flow cross-section of the area difference between the inlet cross-section of the exhaust gas silencer and the exhaust jet cross-section by means of at least one screen having the form of a truncated cone with the smaller opening facing the thrust pipe opening of the jet engine and arranged adjacent to the inlet opening of the exhaust gas silencer so as to surround the exhaust gas concentrically, and varying the flow resistance of sound-absorbing adjustable panels forming at least a portion of the hangar walls or varying the free flow cross-section between the panels such that the air pressure in the hangar does not drop below a predetermined value.