SCORES - Web-based rocket propulsion analysis for space transportation system design

Way, David W.; Olds, John R.

doi:10.2514/6.1999-2353

Cited by 17 publications

(18 citation statements)

References 3 publications

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“…The sizing parameter, k, has a historical average value of k 520 Btu=s=lbf based on data from 28 engines [18]. A value of k 600 Btu=s=lbf was used for this study, representing the use of advanced technologies in engines for a next-generation RLV.…”

Section: A Propulsion Toolmentioning

confidence: 99%

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Evaluation of Multidisciplinary Optimization Techniques Applied to a Reusable Launch Vehicle

Brown

Olds

2006

Journal of Spacecraft and Rockets

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Three multilevel multidisciplinary optimization techniques, Bi-Level Integrated System Synthesis, Collaborative Optimization, and Modified Collaborative Optimization, are applied to the design of a reusable launch vehicle, evaluated, and compared in this study. In addition to comparing the techniques against each other, they are also compared with designs reached via fixed-point iteration of disciplines with local optimization and the industry accepted multidisciplinary optimization technique, All-at-Once. The new multidisciplinary optimization techniques, particularly Bi-Level Integrated System Synthesis, showed greater ability than fixed-point iteration to design for a global objective and were more applicable to complex systems than All-at-Once. This study was the first time that the novel multidisciplinary optimization methods were compared qualitatively and quantitatively under controlled experimentation practices. It is still impossible to statistically determine whether any one of the novel multidisciplinary optimization techniques is better than another, because more studies using different test problems corroborating the conclusions made here are needed. Nomenclature A = area c = characteristic exhaust velocity c F = thrust coefficient g = inequality constraint h = equality constraint/enthalpy/altitude Isp = specific impulse _ m = mass rate MR = mass ratio, W gross =W insertion P = power p = pressure Perf = performance Prop = propulsion r = fuel to oxidizer mixture ratio (propellant mixture ratio) S = wing area SF = scale factor T = thrust W = weight w = weighting factor (for BLISS) W&S = weights and sizing X = input or design variable Y = output or behavior variable V = change in velocity " = nozzle expansion ratio _ = pitch angle rate = design objective Subscripts c = combustor e = exit eng = engine loc = local o = optimized ref = reference req = required sh = shared input to multiple CAs but not calculated by any CA (for BLISS) SL = sea-level sys = system t = throat vac = vacuum veh = vehicle Superscripts pf = performance (for CO and MCO) pp = propulsion (for CO and MCO) t = target from system optimizer (for CO and MCO) ws = weights and sizing (for CO and MCO) = output passed to a CA (for BLISS) = output from a CA to system (for BLISS)

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Section: A Propulsion Toolmentioning

confidence: 99%

“…Therefore, a low-fidelity estimate was calculated based on historical data of rocket engine power to weight ratio (P=W) [18]. This calculation is as follows:…”

Section: A Propulsion Toolmentioning

confidence: 99%

Evaluation of Multidisciplinary Optimization Techniques Applied to a Reusable Launch Vehicle

Brown

Olds

2006

Journal of Spacecraft and Rockets

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“…Another drawback of these simplified codes is their inability to calculate the engine weight directly by estimating individual component weights. The engine thrust-to-weight is typically either an input or estimated from techniques such as one developed by Way et al [41].…”

Section: Case Study #1: Lsammentioning

confidence: 99%

Characterizing high-energy-density propellants for space propulsion applications

et al. 2009

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A technique for computationally determining the thermophysical properties of high-energy-density matter (HEDM) propellants is presented. HEDM compounds are of interest in the liquid rocket engine industry due to their high density and high energy content relative to existing industry-standard propellants. In order to accurately model rocket engine performance, cost and weight in a conceptual design environment, several thermodynamic and physical properties are required over a range of temperatures and pressures. The approach presented here combines quantum mechanical and molecular dynamic (MD) calculations and group additivity methods. A method for improving the force field model coefficients used in the MD is included. This approach is used to determine thermophysical properties for two HEDM compounds of interest: quadricyclane and 2-azido-N,N-dimethylethanamine (DMAZ). The modified force field approach provides results that more accurately match experimental data than the unmodified approach. Launch vehicle and Lunar lander case studies are presented to quantify the system level impact of employing quadricyclane and DMAZ rather than industry standard propellants. In both cases, the use of HEDM propellants provides reductions in vehicle mass compared to industry standard propellants. The results demonstrate that HEDM propellants can be an attractive technology for future launch vehicle and Lunar lander applications.

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“…Therefore, a low-fidelity estimate was calculated based on historical data of rocket engine power to weight ratio (P/W). 9 This calculation is as follows: …”

Section: A Propulsion Toolmentioning

confidence: 99%

“…9 A value of k = 600 BTU/s/lbf was used for this study, representing the use of advanced technologies in engines for a next-generation RLV.…”

Section: A Propulsion Toolmentioning

confidence: 99%

Evaluation of Multidisciplinary Optimazation (MDO) Techniques Applied to a Reusable Launch Vehicle

Brown

Olds

2005

43rd AIAA Aerospace Sciences Meeting and Exhibit

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Three of the most promising multi-level MDO techniques, Bi-Level Integrated System Synthesis (BLISS), Collaborative Optimization (CO) and Modified CollaborativeOptimization (MCO) are applied to the design of a reusable launch vehicle (RLV), evaluated and compared in this study. Apart from comparing the techniques against each other, they are also compared with designs reached via fixed-point iteration (FPI) of disciplines with local optimization and the industry accepted MDO technique, All-at-Once (AAO). The new MDO techniques, particularly BLISS, showed greater ability than FPI to design for a global objective and were more applicable to complex systems than AAO. This study was the first time that the novel MDO methods were compared qualitatively and quantitatively under controlled experimentation practices. It is still impossible to statistically determine if any one of the novel-MDO techniques is better than another as more studies corroborating the conclusions made here are needed. Nomenclaturegrade point average h = equality constraint / enthalpy / altitude INC = incomplete Isp = specific impulse ISS = International Space Station LH2 = liquid hydrogen LOX = liquid oxygen MCO = Modified Collaborative Optimization MDA = multidisciplinary analysis MDO = multidisciplinary optimization MER = mass estimating relationship MoFD = Method of Feasible Directions MR = mass ratio (=W gross /W insertion ) OBD = Optimizer Based Decomposition OMS = orbital maneuvering system P = power p = pressure Perf = Performance POST = Program to Optimize Simulated Trajectories Prop = Propulsion r = fuel to oxidizer mixture ratio (propellant mixture ratio) RCS = reaction control system REDTOP = Rocket Engine Design Tool for Optimal Performance RLV = reusable launch vehicle RSE = response surface equation RSM = response surface model S = wing area SLP = Sequential Linear Programming SQP = Sequential Quadratic Programming SSTO = single stage to orbit T = thrust TRF = technology reduction factor W = weight w = weighting factor (for BLISS) W&S = Weights & Sizing X = input or design variable Y = output or behavior variable ∆V = change in velocity ε = nozzle expansion ratio θ = pitch angle rate Φ = design objective Subscripts c = combustor e = exit eng = engine loc = local o = optimized ref = reference req = required sh = shared input to multiple CA's but not calculated by any CA (for BLISS) SL = sea-level sys = system t = throat vac = vacuum veh = vehicle Superscripts * = output passed to a CA (for BLISS) ^ = output from a CA to system (for BLISS) pf = Performance (for CO and MCO) pp = Propulsion (for CO and MCO) t = target from system optimizer (for CO and MCO) ws = Weights & Sizing (for CO and MCO) American Institute of Aeronautics and Astronautics 2 Downloaded by Stanford University on October 7, 2012 | http://arc.aiaa.org |

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SCORES - Web-based rocket propulsion analysis for space transportation system design

Cited by 17 publications

References 3 publications

Evaluation of Multidisciplinary Optimization Techniques Applied to a Reusable Launch Vehicle

Evaluation of Multidisciplinary Optimization Techniques Applied to a Reusable Launch Vehicle

Characterizing high-energy-density propellants for space propulsion applications

Evaluation of Multidisciplinary Optimazation (MDO) Techniques Applied to a Reusable Launch Vehicle

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