Abstract: In accordance with embodiments disclosed herein, there are provided methods, systems, and apparatuses for predicting whether a point on a computer-generated aircraft or vehicle surface is adjacent to laminar or turbulent flow is made using a transition prediction technique. A plurality of boundary-layer properties at the point are obtained from a steady-state solution of a fluid flow in a region adjacent to the point. Included in the list of boundary-layer properties are computed coefficients or weights of mode shapes that describe the boundary-layer profiles. A plurality of instability modes are obtained, each defined by one or more mode parameters. A vector of regressor weights is obtained for the known instability growth rates in a training dataset. For each instability mode in the plurality of instability modes, a covariance vector is determined, which is the covariance of a predicted local growth rate with the known instability growth rates.

Abstract: In accordance with embodiments disclosed herein, there are provided methods, systems, and apparatuses for predicting whether a point on a computer-generated aircraft or vehicle surface is adjacent to laminar or turbulent flow is made using a transition prediction technique. A plurality of boundary-layer properties at the point are obtained from a steady-state solution of a fluid flow in a region adjacent to the point. Included in the list of boundary-layer properties are computed coefficients or weights of mode shapes that describe the boundary-layer profiles. A plurality of instability modes are obtained, each defined by one or more mode parameters. A vector of regressor weights is obtained for the known instability growth rates in a training dataset. For each instability mode in the plurality of instability modes, a covariance vector is determined, which is the covariance of a predicted local growth rate with the known instability growth rates.

Abstract: A fluid-flow simulation over a computer-generated surface is generated using a diffusion technique. The surface is comprised of a surface mesh of polygons. A boundary-layer fluid property is obtained for a subset of the polygons of the surface mesh. A gradient vector is determined for a selected polygon, the selected polygon belonging to the surface mesh but not one of the subset of polygons. A maximum and minimum diffusion rate is determined along directions determined using the gradient vector corresponding to the selected polygon. A diffusion-path vector is defined between a point in the selected polygon and a neighboring point in a neighboring polygon. An updated fluid property is determined for the selected polygon using a variable diffusion rate, the variable diffusion rate based on the minimum diffusion rate, maximum diffusion rate, and the gradient vector.

Abstract: Improved supersonic laminar flow wing structure, on a supersonic aircraft, having strake extending forwardly of the wing inboard extent, and reversed fillet at strake junction with the wing leading edge. Plain and split flap structures may also be provided at each laminar flow wing.

Abstract: Improved supersonic laminar flow wing structure, on a supersonic aircraft, having strake extending forwardly of the wing inboard extent, and reversed fillet at strake junction with the wing leading edge.

Abstract: Fluid-flow simulation over a computer-generated surface is generated using inviscid and viscous simulations. A fluid-flow mesh of fluid cells is obtained. At least one inviscid fluid property for the fluid cells is determined using an inviscid fluid simulation that does not simulate fluid viscous effects. A set of intersecting fluid cells that intersects the surface are identified. A surface mesh polygon of the surface mesh is identified for each intersecting fluid cell. At least one boundary-layer fluid property for each identified surface mesh polygon is determined using the at least one inviscid fluid property of the corresponding intersecting fluid cell and a boundary-layer simulation that simulates fluid viscous effects.

Abstract: A fluid-flow simulation over a computer-generated surface is generated using a quasi-simultaneous technique. The simulation includes a fluid-flow mesh of inviscid and boundary-layer fluid cells. An initial fluid property for an inviscid fluid cell is determined using an inviscid fluid simulation that does not simulate fluid viscous effects. An initial boundary-layer fluid property a boundary-layer fluid cell is determined using the initial fluid property and a viscous fluid simulation that simulates fluid viscous effects. An updated boundary-layer fluid property is determined for the boundary-layer fluid cell using the initial fluid property, initial boundary-layer fluid property, and an interaction law. The interaction law approximates the inviscid fluid simulation using a matrix of aerodynamic influence coefficients computed using a two-dimensional surface panel technique and a fluid-property vector.

Abstract: In combination, an aircraft and a rotatively combined electrical power/generator and hydraulic motor/pump configured to provide either hydraulic power from electrical power, or electrical power from hydraulic power, installed in said aircraft.

Abstract: A prediction of whether a point on a computer-generated surface is adjacent to laminar or turbulent flow is made using a transition prediction technique. A plurality of instability modes are obtained, each defined by one or more mode parameters. A vector of regressor weights is obtained for the known instability growth rates in a training dataset. For an instability mode in the plurality of instability modes, a covariance vector is determined. A predicted local instabilty growth rate at the point is determined using the covariance vector and the vector of regressor weights. Based on the predicted local instability growth rate, an n-factor envelope at the point is determined.

Abstract: In accordance with embodiments disclosed herein, there are provided methods, systems, and apparatuses for predicting whether a point on a computer-generated aircraft or vehicle surface is adjacent to laminar or turbulent flow is made using a transition prediction technique. A plurality of boundary-layer properties at the point are obtained from a steady-state solution of a fluid flow in a region adjacent to the point. Included in the list of boundary-layer properties are computed coefficients or weights of mode shapes that describe the boundary-layer profiles. A plurality of instability modes are obtained, each defined by one or more mode parameters. A vector of regressor weights is obtained for the known instability growth rates in a training dataset. For each instability mode in the plurality of instability modes, a covariance vector is determined, which is the covariance of a predicted local growth rate with the known instability growth rates.

Abstract: A fluid-flow simulation over a computer-generated surface is generated using a diffusion technique. The surface is comprised of a surface mesh of polygons. A boundary-layer fluid property is obtained for a subset of the polygons of the surface mesh. A gradient vector is determined for a selected polygon, the selected polygon belonging to the surface mesh but not one of the subset of polygons. A maximum and minimum diffusion rate is determined along directions determined using the gradient vector corresponding to the selected polygon. A diffusion-path vector is defined between a point in the selected polygon and a neighboring point in a neighboring polygon. An updated fluid property is determined for the selected polygon using a variable diffusion rate, the variable diffusion rate based on the minimum diffusion rate, maximum diffusion rate, and the gradient vector.

Abstract: Fluid-flow simulation over a computer-generated surface is generated using inviscid and viscous simulations. A fluid-flow mesh of fluid cells is obtained. At least one inviscid fluid property for the fluid cells is determined using an inviscid fluid simulation that does not simulate fluid viscous effects. A set of intersecting fluid cells that intersects the surface are identified. A surface mesh polygon of the surface mesh is identified for each intersecting fluid cell. At least one boundary-layer fluid property for each identified surface mesh polygon is determined using the at least one inviscid fluid property of the corresponding intersecting fluid cell and a boundary-layer simulation that simulates fluid viscous effects.

Abstract: A prediction of whether a point on a computer-generated surface is adjacent to laminar or turbulent flow is made using a transition prediction technique. A plurality of boundary-layer properties at the point are obtained from a steady-state solution of a fluid flow in a region adjacent to the point. A plurality of instability modes are obtained, each defined by one or more mode parameters. A vector of regressor weights is obtained for the known instability growth rates in a training dataset. For each instability mode in the plurality of instability modes, a covariance vector is determined, which is the covariance of a predicted local growth rate with the known instability growth rates. Each covariance vector is used with the vector of regressor weights to determine a predicted local growth rate at the point. Based on the predicted local growth rates, an n-factor envelope at the point is determined.

Abstract: Fluid-flow simulation over a computer-generated aircraft surface is generated using inviscid and viscous simulations. A fluid-flow mesh of fluid cells is obtained. At least one inviscid fluid property for the fluid cells is determined using an inviscid fluid simulation that does not simulate fluid viscous effects. A set of intersecting fluid cells that intersects the aircraft surface are identified. One surface mesh polygon of the surface mesh is identified for each intersecting fluid cell. A boundary-layer prediction point for each identified surface mesh polygon is determined. At least one boundary-layer fluid property for each boundary-layer prediction point is determined using the at least one inviscid fluid property of the corresponding intersecting fluid cell and a boundary-layer simulation that simulates fluid viscous effects. At least one updated fluid property for at least one fluid cell is determined using the at least one boundary-layer fluid property and the inviscid fluid simulation.

Abstract: Aircraft configured to operate at Mach numbers from above 0.80 and up to 1.2 with wing sweep angles defined by the wing outboard leading edge of less than 35 degrees, and incorporating calculated values of the ratio of outboard wing panel aspect ratio raised to an exponent of 0.78, divided by the ratio of maximum thickness divided by chord (t/c), greater than about 45, characterized by one of the following: a) where maximum thickness divided by chord (t/c) is at a location approximately 70% of the distance outboard from the attaching aircraft body to the wing tip, or b) where maximum thickness divided by chord (t/c) is the average value of (t/c)'s located between approximately 50% of the distance outboard from the attaching aircraft body to the wing tip.

Abstract: A fluid-flow simulation over a computer-generated aircraft surface is generated using a diffusion technique. The surface is comprised of a surface mesh of polygons. A boundary-layer fluid property is obtained for a subset of the polygons of the surface mesh. A pressure-gradient vector is determined for a selected polygon, the selected polygon belonging to the surface mesh but not one of the subset of polygons. A maximum and minimum diffusion rate is determined along directions determined using a pressure gradient vector corresponding to the selected polygon. A diffusion-path vector is defined between a point in the selected polygon and a neighboring point in a neighboring polygon. An updated fluid property is determined for the selected polygon using a variable diffusion rate, the variable diffusion rate based on the minimum diffusion rate, maximum diffusion rate, and angular difference between the diffusion-path vector and the pressure-gradient vector.

Abstract: In a jet engine having a plug nozzle and a plug extending rearwardly from the nozzle exit, the improvement comprising a plug having successive cross sections spaced apart rearwardly of the nozzle exit, the cross sections transitioning from circular or near circular at the exit plane defined at the nozzle exit, to progressively non-circular, rearwardly.

Abstract: On an aircraft designed for maximum efficient cruise speed in the range from about Mach 0.8 to about Mach 1.2, and having fuselage and wings with: (a) less than about 25 degrees of leading edge sweep, in combination with airfoil thickness to chord ratios between about 3% and about 8%, as an average along the wing semi-span outboard from the zone of substantial fuselage influence, and (b) wing leading edge sweep between about 20 degrees and about 35 degrees, in combination with airfoil thickness to chord ratios equal to or below about 3% as an average along the semi-span outboard from the zone of substantial fuselage influence to the wing tip.

Abstract: A method of providing an aircraft having a fuselage and a wing configured for extensive laminar flow at design cruise conditions, the method characterized by a) providing wing biconvex-type airfoils having values of thickness, chord and shape along the wing span which provide substantially optimal aircraft range at design cruise conditions, considering the influences of wing drag and wing weight; b) providing wing leading edges, which are configured to effect laminar flow; c) providing fuselage and wing contours which, in combination, produce reduced total wave drag and produce extensive areas of laminar boundary layer flow on the wing; and d) providing wing sweep angularity that facilitates provision of a), b) and c).

Abstract: Jet engine inlet structure of a supersonic aircraft comprising the structure having an inlet ramp and an cowl lip spaced outwardly of the ramp so that entering air flows between the ramp and lip, the lip and ramp configured to produce a first oblique shock that extends outwardly from a forward portion of the ramp to pass ahead of the lip, and a terminal shock that extends outwardly from a rearward portion of the ramp to one of the following xo) a region just ahead of the lip xl) substantially to said lip. A non-uniform shock system is created that generates a central region of nearly isentropic compression and relatively ram recovery and an outer region of reduced ram recovery but entailing reduced cowl angle and drag. Translating cowl structure and also nozzle integration with the fuselage contour to reduce boat tail drag are also provided.