scholarly journals The Langmuir Probe Onboard CSES: data inversion analysis method and first results

2018 ◽  
Vol 2 (6) ◽  
pp. 1-10 ◽  
Author(s):  
Rui Yan ◽  
◽  
YiBing Guan ◽  
XuHui Shen ◽  
JianPing Huang ◽  
...  
Author(s):  
Marvin Schmidt ◽  
Andreas Schütze ◽  
Stefan Seelecke

Energy saving and environmental protection are topics of growing interest. In the light of these aspects alternative refrigeration principles become increasingly important. Shape memory alloys (SMA), especially NiTi alloys, generate a large amount of latent heat during solid state phase transformations, which can lead to a significant cooling effect in the material. These materials do not only provide the potential for an energy-efficient cooling process, they also minimize the impact on the environment by reducing the need for conventional ozone-depleting refrigerants. Our paper, presenting first results obtained in a project within the DFG Priority Program SPP 1599 “Ferroic Cooling”, focuses on the thermodynamic analysis of a NiTi-based cooling system. We first introduce a suitable cooling process and subsequently illustrate the underlying mechanisms of the process in comparison with the conventional compression refrigeration system. We further introduce a graphical solution to calculate the energy efficiency ratio of the system. This thermodynamic analysis method shows the necessary work input and the heat absorption of the SMA in stress/strain- or temperature/entropy-diagrams, respectively. The results of the calculations underline the high potential of this solid-state cooling methodology.


2015 ◽  
Vol 42 (21) ◽  
pp. 8846-8853 ◽  
Author(s):  
R. E. Ergun ◽  
M. W. Morooka ◽  
L. A. Andersson ◽  
C. M. Fowler ◽  
G. T. Delory ◽  
...  

2020 ◽  
Vol 37 (7) ◽  
pp. 2229-2249
Author(s):  
Chunhui Ma ◽  
Jie Yang ◽  
Lin Cheng ◽  
Li Ran

Purpose To improve the efficiency, accuracy and adaptivity of the parameter inversion analysis method of a rockfill dam, this study aims to establish an adaptive model based on a harmony search algorithm (HS) and a mixed multi-output relevance vector machine (MMRVM). Design/methodology/approach By introducing the mixed kernel function, the MMRVM can accurately simulate the nonlinear relationship between the material parameters and dam settlement. Therefore, the finite element method with time consumption can be replaced by the MMRVM. Because of its excellent global search capability, the HS is used to optimize the kernel parameters of the MMRVM and the material parameters of a rockfill dam. Findings Because the parameters of the HS and the variation range of the MMRVM parameters are relatively fixed, the HS-MMRVM can imbue the inversion analysis with adaptivity; the number of observation points required and the robustness of the HS-MMRVM are analyzed. An application example involving a concrete-faced rockfill dam shows that the HS-MMRVM exhibits high accuracy and high speed in the parameter inversion analysis of static and creep constitutive models. Practical implications The applicability of the HS-MMRVM in hydraulic engineering is proved in this paper, which should further validate in inversion problems of other fields. Originality/value An adaptive inversion analysis model is established to avoid the parameters of traditional methods that need to be set by humans, which strongly affect the inversion analysis results. By introducing the mixed kernel function, the MMRVM can accurately simulate the nonlinear relationship between the material parameters and dam settlement. To reduce the data dimensions and verify the model’s robustness, the number of observation points required for inversion analysis and the acceptable degree of noise are determined. The confidence interval is built to monitor dam settlement and provide the foundation for dam monitoring and reservoir operation management.


Author(s):  
Ole Detlefsen ◽  
Lasse Theilen ◽  
Moustafa Abdel-Maksoud

This paper presents a static and a time-domain method to assess the position-keeping capability of monohull vessels. For the static analysis method, the equlibrium between mean environmental loads and available actuator forces is determined. In case of the dynamic assessment, the motions of the fully actuated ship in all degrees of freedom are simulated in time domain and evaluated by criteria regarding the position and heading of the ship. After first results from validation tests an exemplary application is shown by assessing the positioning capability of a Voith-Schneider propelled offshore supply vessel.


2006 ◽  
Vol 54 (5) ◽  
pp. 472-486 ◽  
Author(s):  
J.-P. Lebreton ◽  
S. Stverak ◽  
P. Travnicek ◽  
M. Maksimovic ◽  
D. Klinge ◽  
...  

1997 ◽  
Vol 35 (7) ◽  
pp. 269-278 ◽  
Author(s):  
A. Weingartner ◽  
E. Schäfer ◽  
K. Staubmann ◽  
W. Urban ◽  
W. Loiskandl ◽  
...  

A new adsorption procedure showed that adsorption competition can be successfully influenced in favour of organic micropollutants by generating variable velocity fields and thus reducing the adsorption of competing harmless natural organic matter (NOM). A satisfying optimisation of the method can effectively be done with the help of a mathematical model. The model to be developed had to meet two main targets: firstly, it had to be able to simulate the adsorption processes under hydraulic conditions that change with time and space, and secondly, the implementation of the carbon fouling effect had to be improved. First results showed that the calculated breakthrough curves agreed to experimental data. However, batch experiment results indicated that the assumption of adsorption reversibility is only valid for some substances, which is important to consider when modelling competitive adsorption. An improved adsorption analysis method that integrates kinetic behaviour of NOM is expected to give evidence about NOM's carbon fouling properties.


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