Data Analysis of Phoenix Reusable Launch Vehicle Demonstrator Flight Test

Jategaonkar, R.V.; Behr, R.; Gockel, W.; Zorn, Christoph

doi:10.2514/1.19602

Cited by 7 publications

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our RLV has wing area S 2370 ft 2 and mass m 4211.5 slugs (weight W mg 135; 500 lbf), and therefore its wing loading is W∕S 57.2 psf. Note that the wing loadings for other RLVs such as the Space Shuttle [19], X-34 [20], Phoenix [21], and HORUS-2B [16] are 69.9, 50.4, 23.9, and 48.5 psf, respectively. Drag coefficient for the RLV is computed using the standard drag polar equation:…”

Section: B Vehicle Modelmentioning

confidence: 99%

Approach and Landing Range Guidance for an Unpowered Reusable Launch Vehicle

Kluever

Neal

2015

Journal of Guidance, Control, and Dynamics

View full text Add to dashboard Cite

A new method has been developed for predicting and controlling the ground range of an unpowered reusable launch vehicle. The key feature is the use of the quasi-equilibrium glide condition to create a database of range-togo versus energy for different values of the glide-efficiency factor. Downtrack range to runway touchdown is predicted by performing a two-dimensional table lookup of the range-to-go database. Unlike most predictorcorrector guidance methods, the proposed ground-range guidance scheme does not require onboard numerical integration of the governing equations of motion. Another key element is the coupling between the latter stages of the traditional terminal area energy management phase and the entire approach and landing phase, where the flare-to-touchdown maneuver is concisely parameterized by an exponential altitude profile. Numerical simulations demonstrate that this new method can accurately and reliably guide the vehicle to the desired touchdown conditions despite large errors in the initial states, large errors in the initial downtrack distance to the runway, and aerodynamic drag dispersions. Nomenclaturelbf E = energy height, ft g = 32.174 ft∕s 2 , Earth's gravitational acceleration h = altitude, ft K = lift-induced drag coefficient parameter K H = altitude error gain, 1∕ft K HD = altitude rate error gain, s∕ft K γ = flight-path angle error gain K q = dynamic pressure error gain, ft 2 ∕lbf L = lift force, lbf M = Mach number m = vehicle mass, slug q = dynamic pressure, lbf∕ft 2 R = ground range, ft R go = range-to-go, ft S = vehicle reference area, ft 2 s = downtrack distance relative to runway touchdown, ft t = time, s V = airspeed, ft∕s x = downtrack position along runway centerline, ft γ = flight-path angle, rad η = glide-efficiency factor ρ = atmospheric density, slug∕ft 3 σ = exponential decay constant for flare maneuver, ft Subscripts 0 = initial value ALI = approach and landing interface EG = equilibrium glide F = start of flare maneuver flare = flare maneuver max = maximum QEG = quasi-equilibrium glide TD = touchdown Superscript * = maximum lift-to-drag ratio

show abstract

Section: B Vehicle Modelmentioning

confidence: 99%

Approach and Landing Range Guidance for an Unpowered Reusable Launch Vehicle

Kluever

Neal

2015

Journal of Guidance, Control, and Dynamics

View full text Add to dashboard Cite

show abstract

“…Kaplan (2002) provided an overview of different configurations that would allow for RLVs to be fully re-usable. Jategaonkar et al (2006) demonstrated that the United States is moving forward in the research of RLVs by successfully completing three automatic landing tests of an unpowered horizontal landing re-usable launch vehicle. *Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

Quantification of epistemic uncertainty in re-usable launch vehicle aero-elastic design

King

Grandhi

Benanzer

2012

Engineering Optimization

View full text Add to dashboard Cite

Due to the inherent natural variability of parameters with re-usable launch vehicles, design without consideration of reliability measures may be unreliable and vulnerable to failure. Generally, in preliminary air vehicle design little information is known regarding design variable uncertainties, therefore requiring a technique that can quantify epistemic uncertainties. Evidence theory is employed to accomplish this task resulting in a reliability bound of belief and plausibility. Due to the discontinuous nature of the belief and plausibility function it is necessary to implement a continuous function known as plausibility decision to be used to calculate sensitivities that can be implemented in a gradient-based reliability-based design optimization algorithm. This research develops a new plausibility decision approximation that calculates sensitivities with respect to uncertain variables without introducing extra computational cost or numerical integration. This new metric was demonstrated in a sensitivity analysis of the aero-elastic flutter reliability of a re-usable launch vehicle's wing.

show abstract

“…analysis of a scaled, unmanned re-entry vehicleThe PHOENIX vehicle was a one-seventh scale model of the future space transport vehicle HOPPER, developed by ASTRIUM[55]. The vehicle particularly served for acquiring real flight and landing attitude data that cannot be simulated.…”

mentioning

confidence: 99%

Recent developments at the numerical simulation of landing gear dynamics

Krüger

Morandini

2011

CEAS Aeronaut J

View full text Add to dashboard Cite

Aircraft landing gears support the aircraft during ground operations, including take-off, landing impact, taxiing, gate handling and maintenance. Mostly for reasons of minimum mass and ground clearance, landing gears are slender structures which exhibit a considerable dynamic response to ground load excitations. As the landing gear is one of the few systems on the aircraft without redundancies, the knowledge of landing gear dynamics is crucial for aircraft design and aircraft safety. Simulation of landing gear dynamics is a cornerstone of aircraft loads analysis, as well for vertical loads resulting from touch-down as for longitudinal and lateral loads resulting from braking, steering and towing. Another important field of interest is landing gear vibrations like gear walk and shimmy. Those phenomena can be brake induced or result from tire spin-up at touchdown or simply from a coupling of dynamics of the running tire and structural mechanics of the landing gear leg. All those effects strongly depend on a number of parameters such as aircraft speed, landing gear vertical deflection, tire pressure and wear of the parts. Many of those parameters can only be estimated and might change during the operation of the aircraft. Numerical investigation is thus a challenging task. Analysis methods exist both in the frequency domain and in the time domain. As stability analysis is straight forward in frequency domain methods, this approach is still often used. However, in many cases nonlinearities are dominant which lead to limit-cycle characteristics of the vibrations. Here, multibody modelling or a mixture of multibody and finite element modelling including time domain simulation is used. In the article, a general outline is given of how vibration problems in landing gears can be treated by numerical analysis methods. The article will start with a classification of typical problems, give a short overview of classical papers, and explain typical approaches. In addition, alternative approaches for stability analysis and for the detection of limit-cycle oscillations as well as state-ofthe-art modelling approaches will be presented.

show abstract

Data Analysis of Phoenix Reusable Launch Vehicle Demonstrator Flight Test

Cited by 7 publications

References 2 publications

Approach and Landing Range Guidance for an Unpowered Reusable Launch Vehicle

Approach and Landing Range Guidance for an Unpowered Reusable Launch Vehicle

Quantification of epistemic uncertainty in re-usable launch vehicle aero-elastic design

Recent developments at the numerical simulation of landing gear dynamics

Contact Info

Product

Resources

About