Costa Rica tiene una rica hidrografía con abundantes cuencas hidrográficas a pesar de su pequeño tamaño. El país tiene tres vertientes principales: la vertiente del Caribe, la vertiente del Pacífico y la sub-vertiente Norte. Los ríos de la vertiente del Caribe son largos, anchos y caudalosos, y mantienen su caudal durante todo el año, mientras que los ríos de la vertiente del Pacífico son más cortos y pierden parte de su caudal durante la época seca. La población aprovecha
Costa Rica tiene una rica hidrografía con abundantes cuencas hidrográficas a pesar de su pequeño tamaño. El país tiene tres vertientes principales: la vertiente del Caribe, la vertiente del Pacífico y la sub-vertiente Norte. Los ríos de la vertiente del Caribe son largos, anchos y caudalosos, y mantienen su caudal durante todo el año, mientras que los ríos de la vertiente del Pacífico son más cortos y pierden parte de su caudal durante la época seca. La población aprovecha
Lecture on “Aerodynamic design of Aircraft” in University of Tokyo 21st December, 2015. Optimization techniques, data-visualization and their applications are inclusive.
This document summarizes research on the design optimization of a launch vehicle concept using a clustered hybrid rocket engine for future space transportation. The researchers developed a design methodology for a launch vehicle with clustered hybrid rocket engines and investigated combinations of unit engines. Their objectives were to maximize payload to gross weight ratio and minimize gross weight. They defined four design cases and used multi-objective genetic algorithms and data visualization techniques to optimize the design variables. The results showed that a design with optimized engines for each stage performed best by avoiding excess unburnt fuel from shared engines across stages. Future work could further reduce unburnt fuel and improve payload ratio.
Multi-objective Genetic Algorithm Applied to Conceptual Design of Single-stag...Masahiro Kanazaki
"Multi-objective Genetic Algorithm Applied to Conceptual Design of Single-stage Rocket Using Hybrid Propulsion System" presented at The Eighth China-Japan-Korea Joint Symposium on Optimization of Structural and Mechanical Systems (CJK-OSM).
This document describes using efficient global optimization applied to wind tunnel experiments to optimize flow control by plasma actuators. The optimization method uses a Kriging surrogate model and genetic algorithm to select additional sampling locations for wind tunnel runs to improve the model. Over 20 runs, it identified design variables that minimized drag for different plasma actuator configurations. Design A achieved the lowest drag by reducing flow separation with high duty cycle and modulation frequency settings. Design B also reduced drag with lower electrical energy requirements. The automated optimization successfully integrated wind tunnel experiments to efficiently optimize plasma actuator control parameters.
MULTI-POINT DESIGN OF A SUPERSONIC WING USING MODIFIED PARSEC AIRFOIL REPRESE...Masahiro Kanazaki
1) The study aimed to perform multi-point aerodynamic design of a supersonic wing using an efficient global optimization methodology.
2) The methodology used a modified PARSEC airfoil representation and kriging model-based genetic algorithm for efficient global optimization.
3) The design explored maximizing lift-to-drag ratio at high and low Mach cruise speeds, finding many potential designs and discovering that camber of the kink and root airfoils most affected performance at high Mach while thickness curvature at kink and root did so at low Mach.
3. はじめに(2/5)
• 多段式ハイブリッドロケット設計*とその特徴
– 考慮すべき設計変数は一段10個となり,多段とすると30個
を超える
– 時間変化を伴う変数も多い
– 遺伝的アルゴリズムにより効率的な解決
多変量問題をどう観察するか?体系的知識とするか?
現状のLVはペイロード/全備重量が1%に満たない
→ 各段の燃焼方式自体
を最適に選択できないか?
→WG内で提案されている検討すると125ケース
(5個の方式から3つ重複を許して並べる重複順列)
*Kitagawa, Y., Kitagawa, K., Nakamiya, M., Kanazaki, M., and Shimada, T., Transactions of the Japan Society for Aeronautical and Space Sciences, Vol. 55 No.4, 2012.
3
6. はじめに(5/5)
• 知識獲得法の例 • 何れの手法も分かり
易い点がメリット
• 散布図行列/並行座
標表示では要素の並
べ方によって雰囲気
散布図行列** が変わってしまう,全
体の傾向は捉えやす
いが要素ごとの特徴
は逐一チェックする必
要がある.
• 分散解析では特に目
的関数への寄与が無
い設計変数について
平行座標表示* 分散解析** の知識は得られない.
*Kitagawa, Y., Kitagawa, K., Nakamiya, M., Kanazaki, M., and Shimada, T., T Japan Society for Aeronautical and Space Sciences, Vol. 55 No.4, 2012.
**Kosugi, K., Oyama, A., Fujii, K., and Kanazaki, M., Infotech@aerospace2011, AIAA 2011-1634, March 2011.
6
13. 問題設定(設計変数)
aの範囲は実験(無旋回流)で得られた結果により決定*( r = a ⋅ Gon )
* Hikone,S., et al, “Regression Rate Characteristics and Combustion Mechanism of Some Hybrid Rocket Fuels ,”Asian Joint Conference on
13
Propulsion and Power 2010.
14. HREを用いたLVの評価手法
・燃料グレインの寸法
設計変数
・O/F、燃焼室圧力等の時間履歴
・酸化剤流量
・ O/Fの初期値
構造評価 ・燃料後退速度式の係数
・燃焼室 ・酸化剤タンク ・酸化剤質量流束の初期値
・ノズル ・加圧タンク ・外壁構造 ・燃焼時間
・燃焼室の初期圧力
・加圧タンクの初期圧力
各段のエンジン緒元 ・ノズル開口比
NASA-CEA*による推力計算
軌道計算 *NASA Chemical Equilibrium with Applications
(Gordon, S., et al, “Computer Program for Calculation
No of Complex Chemical Equilibrium Compositions and
設計燃焼時間? Applications I. Analysis,” NASA RP-1311, 1994.)
Yes
各段燃焼終了時の高度・速度・軌道
14