Comparison of a closed-loop control by means of high-fidelity and low-fidelity coupled CFD/RBD computations

2019 ◽  
Vol 234 (10) ◽  
pp. 1611-1623
Author(s):  
Marius Franze
Keyword(s):  
Closed Loop ◽  
Fluid Dynamic ◽  
Flight Mechanics ◽  
High Fidelity ◽  
Dynamic Simulations ◽  
Loop Control ◽  
Rigid Body Dynamic ◽  
Path Control ◽  
Urans Cfd ◽  
Semi Empirical

This work compares the principle of a basic fin-controlled sounding rocket with coupled computational fluid dynamic and rigid body dynamic simulations of two coupling environments: (1) a low-fidelity approach using Missile DATCOM as semi-empirical aerodynamic solver, and (2) a high-fidelity approach using DLR TAU as URANS CFD code. The flight mechanics solver REENT is used in both cases. A closed-loop flight path control is developed and adjusted via low-fi simulations and then verified via high-fi simulations. For simple roll and pitching maneuvers the environments match well, whereas differences can be seen in complex maneuvers, e.g. body–body interactions of separation procedures.

scholarly journals Multifidelity domain-aware learning for the design of re-entry vehicles

2021 ◽  
Author(s):  
Francesco Di Fiore ◽  
Paolo Maggiore ◽  
Laura Mainini
Keyword(s):  
Thermal Protection ◽  
Fluid Dynamic ◽  
Design Solution ◽  
High Fidelity ◽  
Specific Knowledge ◽  
Dynamic Simulations ◽  
Strongly Coupled ◽  
Design And Optimization ◽  
Domain Specific ◽  
Domain Specific Knowledge

AbstractThe multidisciplinary design optimization (MDO) of re-entry vehicles presents many challenges associated with the plurality of the domains that characterize the design problem and the multi-physics interactions. Aerodynamic and thermodynamic phenomena are strongly coupled and relate to the heat loads that affect the vehicle along the re-entry trajectory, which drive the design of the thermal protection system (TPS). The preliminary design and optimization of re-entry vehicles would benefit from accurate high-fidelity aerothermodynamic analysis, which are usually expensive computational fluid dynamic simulations. We propose an original formulation for multifidelity active learning that considers both the information extracted from data and domain-specific knowledge. Our scheme is developed for the design of re-entry vehicles and is demonstrated for the case of an Orion-like capsule entering the Earth atmosphere. The design process aims to minimize the mass of propellant burned during the entry maneuver, the mass of the TPS, and the temperature experienced by the TPS along the re-entry. The results demonstrate that our multifidelity strategy allows to achieve a sensitive improvement of the design solution with respect to the baseline. In particular, the outcomes of our method are superior to the design obtained through a single-fidelity framework, as a result of the principled selection of a limited number of high-fidelity evaluations.

scholarly journals A control-oriented dynamic wind farm model: WFSim

2018 ◽  
Vol 3 (1) ◽  
pp. 75-95 ◽  
Author(s):  
Sjoerd Boersma ◽  
Bart Doekemeijer ◽  
Mehdi Vali ◽  
Johan Meyers ◽  
Jan-Willem van Wingerden
Keyword(s):  
Wind Farm ◽  
Closed Loop ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Wind Farms ◽  
Vertical Dimension ◽  
High Fidelity ◽  
Loop Control ◽  
Starting Point ◽  
Farm Model

Abstract. Wind turbines are often sited together in wind farms as it is economically advantageous. Controlling the flow within wind farms to reduce the fatigue loads, maximize energy production and provide ancillary services is a challenging control problem due to the underlying time-varying non-linear wake dynamics. In this paper, we present a control-oriented dynamical wind farm model called the WindFarmSimulator (WFSim) that can be used in closed-loop wind farm control algorithms. The three-dimensional Navier–Stokes equations were the starting point for deriving the control-oriented dynamic wind farm model. Then, in order to reduce computational complexity, terms involving the vertical dimension were either neglected or estimated in order to partially compensate for neglecting the vertical dimension. Sparsity of and structure in the system matrices make this model relatively computationally inexpensive. We showed that by taking the vertical dimension partially into account, the estimation of flow data generated with a high-fidelity wind farm model is improved relative to when the vertical dimension is completely neglected in WFSim. Moreover, we showed that, for the study cases considered in this work, WFSim is potentially fast enough to be used in an online closed-loop control framework including model parameter updates. Finally we showed that the proposed wind farm model is able to estimate flow and power signals generated by two different 3-D high-fidelity wind farm models.

The Impact of Visual Feedback Type on the Mastery of Visuo-Motor Transformations

2012 ◽  
Vol 220 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Sandra Sülzenbrück
Keyword(s):  
Empirical Research ◽  
Visual Feedback ◽  
Closed Loop ◽  
Motor Planning ◽  
Visual Input ◽  
Closed Loop Control ◽  
Loop Control ◽  
Feedback Type ◽  
Effective Use ◽  
The Impact

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.

118-LB: Glucose Variability throughout the Menstrual Cycle on Closed-Loop Control in Type 1 DM

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 118-LB
Author(s):  
CAROL J. LEVY ◽  
GRENYE OMALLEY ◽  
SUE A. BROWN ◽  
DAN RAGHINARU ◽  
YOGISH C. KUDVA ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Closed Loop ◽  
Glucose Variability ◽  
Closed Loop Control ◽  
Loop Control ◽  
Type 1 Dm

101-LB: Eighteen-Month Use of Closed-Loop Control (CLC): A Randomized, Controlled Trial

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 101-LB
Author(s):  
SUE A. BROWN ◽  
DAN RAGHINARU ◽  
BRUCE A. BUCKINGHAM ◽  
YOGISH C. KUDVA ◽  
LORI M. LAFFEL ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Closed Loop ◽  
Controlled Trial ◽  
Closed Loop Control ◽  
Loop Control ◽  
Randomized Controlled
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