Performance Analysis of Variable-Geometry Scramjet Inlets Using a Low-Order Model

Dalle, Derek J.; Torrez, Sean M.; Driscoll, James F.

doi:10.2514/6.2011-5756

Cited by 24 publications

(23 citation statements)

References 13 publications

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“…The MASIV/MASTrim model has been the subject of many previous papers [16][17][18][19][20][21][22] and is used for this work. Figure 1 illustrates the generic hypersonic vehicle design used for the present work, and the name "MAX-1B" is associated with this vehicle.…”

Section: Dual-mode Ramjet-scramjet Vehicle Modelmentioning

confidence: 99%

Flight Mechanics of Ram-Scram Transition

Dalle

Driscoll

2013

AIAA Atmospheric Flight Mechanics (AFM) Conference

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Among known air-breathing propulsion systems, the system that can be operated over the widest range of flight Mach numbers is the dual-mode ramjet-scramjet. In such an engine, either subsonic combustion or supersonic combustion can occur in a shared flowpath, and the mode of operation is determined by the flight condition and control inputs. Recent research has indicated that the steadystate thrust of such an engine is discontinuous across the transition from one mode to the other. This work discusses evidence for that discontinuity and discuss conditions and strategies required to maintain control through ram-scram transition. Nomenclature a = acceleration A = duct area c p = specific heat at constant pressure C L = lift coefficient C D = drag coefficient I = impulse function K = drag polar coefficient m f = cumulative fuel consumptioṅ m = mass floẇ m f = fuel mass flow rate M = Mach number p = pressure q ∞ = freestream dynamic pressure Q f = specific fuel heat release R = normalized gas constant S = reference area t = time T = temperature u = total flow speed u = vector of control variables V = velocity of vehicle x = vector of state variables γ = ratio of specific heats, flight path angle η c = combustion efficiency ρ = density τ = temporal integration variable

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Section: Dual-mode Ramjet-scramjet Vehicle Modelmentioning

confidence: 99%

Flight Mechanics of Ram-Scram Transition

Dalle

Driscoll

2013

AIAA Atmospheric Flight Mechanics (AFM) Conference

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“…The full inlet design process from [17] is used here except that variable geometry is not considered. Despite the fact the inlet model used here is much simpler than the MASIV inlet model [3], a well-designed inlet has been shown to have the property that simple models predict their performance fairly accurately over a limited range of flight conditions [17].…”

Section: Inlet Designmentioning

confidence: 99%

Continuous Differentiation of Complex Systems Applied to a Hypersonic Vehicle

Dalle

Driscoll

2012

AIAA Atmospheric Flight Mechanics Conference

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An implementation of a three-dimensional model for an air-breathing hypersonic vehicle using algorithmic differentiation is presented. Motivation for this work is given in terms of difficulties encountered while calculating the linearized flight dynamics of another hypersonic vehicle model. The new model automatically calculates derivatives with respect to flight condition variables, control variables, model parameters, and design variables. The differentiation approach used here is unique in that it calculates both left-and right-hand derivatives at first-order discontinuities. Other approaches including complex step and finite difference are compared with the present implementation. Difficulties encountered in the derivation include handling of if statements, iterative solution of systems, and sorting. Hypersonic flight for a simple climbing and accelerating trajectory is considered to demonstrate the use of the model, and the effect of ballast mass on the short-period and Dutch-roll modes is also shown. Nomenclature a = local speed of sound C = transformation matrix e = eccentricity F, F = force or specific force f = mass capture fraction f = vector equations of motion function g = gravity vector H = height h = altitude I = inertia tensor J = Jacobian L = length or geodetic latitude M = Mach number M = moment (torque) or specific moment m = number of external inlet shockṡ m = mass flow rate n = number of internal inlet shocks n = normal vector n = unit normal vector P = roll rate p = pressure Q = pitch rate q = dynamic pressure R = yaw rate r = position vector T = temperature u = vector of control variables V, v, v = velocity w = dimensionless width x, y, z = physical coordinates x = vector of state variables α = angle of attack β = sideslip angle γ = ratio of specific heats or flight path angle δ = deflection angle or control input ε = pressure ratio ζ, η, ξ = placeholder variables θ = pitch angle or angle of flow λ = length fraction ρ = density σ = velocity heading angle φ = roll angle ψ = yaw angle ω, ω = angular velocity Subscripts/superscripts + = right-hand derivative − = left-hand derivative * = reference value 0 = stagnation value 1, 2, . . . = station number b= body frame CE = collective (average) elevon value CR = collective (average) rudder value DE = differential (left minus right) elevon value e = Earth-centered, Earth-fixed frame ER = equivalence ratio i = station index or intertial frame N, E, D = north, east, down components n = navigation frame

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“…NASA investigates a rotary lip VGI for the X-43A hypersonic aircraft [30], and Ref. [31] obtains the adjusting rules and performance variation of VGI in various conditions with numerical simulation method. The Space and Astronautical Science institution of Japan developed a variable geometry axisymmetric inlet for the ATREX engine [32].…”

Section: Introductionmentioning

confidence: 99%

“…Ref. [31] compares the properties of three kinds of VGI using the low-order control-oriented model, and designs a kind of inlet used in a wide range of Mach numbers. Ref.…”

Section: Introductionmentioning

confidence: 99%

Modeling and nonlinear control for air-breathing hypersonic vehicle with variable geometry inlet

Dou

Ding

2017

Aerospace Science and Technology

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This paper develops a control method for an air-breathing hypersonic vehicle with variable geometry inlet (AHV-VGI). For the AHV-VGI, a movable translating cowl is used to track the shock on lip conditions to capture enough air mass flow, which can ensure a more powerful thrust. Compared with traditional air-breathing hypersonic vehicle with fixed geometry inlet (AHV-FGI), this AHV-VGI extends the velocity range, which is favorable to the acceleration and maneuvering flight. However, the VGI causes the unknown changes of the aerodynamic forces, moment and the thrust in the meanwhile. Therefore, we firstly establish a longitudinal dynamic for AHV-VGI, which includes the uncertain changes induced by VGI. A conception of the optimal elongation distance of translating cowl is introduced, and its estimated value is obtained by curve fitted approximation. And then, the control process for AHV-VGI is divided into two subsystems. For each subsystem, a sliding mode controller is designed, and interval type-2 fuzzy logic systems (FLSs) are adopted to approximate nonlinear parts including the uncertain changes induced by VGI. Furthermore, uniformly stability of the whole system is proved by Lyapunov approach. Finally, simulation results demonstrate that AHV have a better control performance under the condition of VGI compared to the FGI.

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Performance Analysis of Variable-Geometry Scramjet Inlets Using a Low-Order Model

Cited by 24 publications

References 13 publications

Flight Mechanics of Ram-Scram Transition

Flight Mechanics of Ram-Scram Transition

Continuous Differentiation of Complex Systems Applied to a Hypersonic Vehicle

Modeling and nonlinear control for air-breathing hypersonic vehicle with variable geometry inlet

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