Two-Dimensional Simulation Model of Steady-state Mixed-flow Grain Drying. Part 2: Experimental Validation

1998 ◽  
Vol 71 (1) ◽  
pp. 51-66 ◽  
Author(s):  
S.A. Giner ◽  
D.M. Bruce
Keyword(s):  
Steady State ◽  
Simulation Model ◽  
Experimental Validation ◽  
Two Dimensional ◽  
Mixed Flow ◽  
Grain Drying ◽  
Dimensional Simulation

Experimental Validation of Towed Underwater Cable Model

2019 ◽  
Author(s):  
Jan Vidar Grindheim ◽  
Antonio Carlos Fernandes ◽  
Joel Sena Sales Junior ◽  
Inge Revhaug
Keyword(s):  
Steady State ◽  
Experimental Validation ◽  
Experimental Results ◽  
Experimental Setup ◽  
Two Dimensional ◽  
Cable Model ◽  
Governing Equations ◽  
Current Channel ◽  
Steady State Condition ◽  
Wet Weight

Abstract Towed underwater cable models have been validated using experimental results performed in the current channel at Laboratório de Ondas e Correntes (LOC) at COPPE/UFRJ, Rio de Janeiro. The numerical simulators utilize a Finite Difference Method to solve the Partial Differential Equations describing the dynamics of a towed underwater cable under tension. A non-dimensional analysis of the system dynamics for the two-dimensional case has been performed, with non-dimensional governing equations being presented. The experimental setup consists of two cable sections of ∼1.5 m length each, the first having 3 mm diameter and slightly positive wet weight while the second section has 2.5 mm diameter and slight negative wet weight. With the cable in steady-state condition, the towpoint is moved 0.50 m sideways and the time for the cable to return to straight tow is measured. Further, the cable depths at midpoint and tail are measured in steady-state. Experiments are performed at currents ranging from 0.17 to 0.47 m/s. The presented experimental results are compared to the numerical results. Reasonable agreements are obtained.

scholarly journals Use of a Two-Dimensional Simulation Model in the Thermal Analysis of a Multi-Board Electronic Module

1994 ◽  
Vol 116 (2) ◽  
pp. 126-133 ◽  
Author(s):  
C. Beckermann ◽  
T. F. Smith ◽  
B. Pospichal
Keyword(s):  
Heat Transfer ◽  
Simulation Model ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Circuit Boards ◽  
Depth Direction ◽  
Wide Range ◽  
Local Board ◽  
Dimensional Simulation ◽  
Effective Component

A study is reported of heat transfer and air flow in an electronic module consisting of an array of narrowly spaced vertical circuit boards with highly-protruding components contained in a naturally vented chassis. A two-dimensional simulation model is developed that accounts for heat transfer by conduction, convection, and radiation, and sensitivity studies are performed. Experiments are conducted using a specially constructed test module. Comparisons with the experiments reveal the need to calibrate the model by selecting an effective component height that represents the drag properties of the actual three-dimensional component geometry. The need to account in the model for heat losses in the depth direction is also discussed. The importance of accurate thermophysical properties and of multi-dimensional radiation is shown. Good agreement with measured velocities and local board temperatures is obtained over a wide range of power levels, and it is concluded that the calibrated model is capable of representing the thermal behavior of the present module.

Using optimization to create self-stable human-like running

Robotica ◽  
2009 ◽  
Vol 27 (3) ◽  
pp. 321-330 ◽  
Author(s):  
Katja Mombaur
Keyword(s):  
Optimal Control ◽  
Simulation Model ◽  
Numerical Optimization ◽  
Humanoid Robots ◽  
Open Loop ◽  
Optimization Techniques ◽  
Model Parameters ◽  
Two Dimensional ◽  
Control Techniques ◽  
Dimensional Simulation

SUMMARYThis paper demonstrates how numerical optimization techniques can efficiently be used to create self-stable running motions for a human-like robot model. Exploitation of self-stability is considered to be a crucial factor for biological running and might be the key for success to make bipedal and humanoid robots run in the future. We investigate a two-dimensional simulation model of running with nine bodies (trunk, thighs, shanks, feet, and arms) powered by external moments at all internal joints. Using efficient optimal control techniques and stability optimization, we were able to determine model parameters and actuator inputs that lead to fully open-loop stable running motions.

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