scholarly journals Thermal Experiments for Validation of 3-AMADEUS Cubesat

2020 ◽  
Author(s):  
Daniel Carvalhais ◽  
Paulo Figueiredo ◽  
Miguel Machado ◽  
André Guerra ◽  
Francisco Brójo
Keyword(s):  
Numerical Study ◽  
Low Cost ◽  
Thermal Control ◽  
Controlled Environment ◽  
Finite Element Software ◽  
Transfer Processes ◽  
View Factors ◽  
Aluminum Plates ◽  
Infrared Lamps ◽  
Orbital Cycle

There has been an increasing interest in CubeSats missions due to its small size, low cost and flexibility to accommodate different payloads. It enables CubeSats to perform a range of various missions. One of the causes of failure in a satellite in space are the temperature peaks suffered during a full orbital cycle. Therefore, proper thermal control system design and test should be performed to guarantee the reliability of a spacecraft prior to launch.The present work aims to analyze the main heat transfer processes within a satellite to validate the 3-AMADEUS CubeSat and current methodologies used by CEiiA for nano and micro satellites. Hence, with the purpose of developing thermal models with higher reliability, an experiment was devised to be performed in a controlled environment. The experimental test consists in a study of the heat exchange between two aluminum plates through radiation, using infrared lamps as heat source. Three distance configuration and two lamp types are tested. This would emulate the heat transmission between different components within the satellite. The view factors are changed. In parallel, a finite element software (MSC Nastran) is used to carry out a numerical study of the same experiments. The temperature distribution results of both numerical and experimental solutions are then compared, and the results are discussed. Keywords: Radiation, View factors, Experimental

scholarly journals Experimental and numerical study on the thermal control strategy for a gas foil bearing enhanced with thermoelectric modules

2020 ◽  
Vol 138 ◽  
pp. 106581 ◽  
Author(s):  
Adam Martowicz ◽  
Jakub Roemer ◽  
Michał Lubieniecki ◽  
Grzegorz Żywica ◽  
Paweł Bagiński
Keyword(s):  
Control Strategy ◽  
Numerical Study ◽  
Thermal Control ◽  
Thermoelectric Modules ◽  
Foil Bearing

scholarly journals Numerical Study of the Seismic Response of an Instrumented Building with Underground Stories

2021 ◽  
Vol 11 (7) ◽  
pp. 3190
Author(s):  
Edmundo Schanze ◽  
Gilberto Leiva ◽  
Miguel Gómez ◽  
Alvaro Lopez
Keyword(s):  
Seismic Response ◽  
Soil Structure ◽  
Numerical Study ◽  
Time History ◽  
Building Design ◽  
Average Height ◽  
The Real ◽  
Vibration Data ◽  
Finite Element Software ◽  
Stiffness Reduction

Engineering practitioners do not usually include soil–structure interactions in building design; rather, it is common to model and design foundations as embedded joints with joint–based reactions. In some cases, foundation structures are modeled as rigid bodies, embedding the first story into lower vertical elements. Given that the effects of underground floors on the seismic response are not generally included in current building design provisions, it has been little explored in the literature. This work compares and analyzes models to study the effects of different underground stories modeling approaches using earthquake vibration data recorded for the 16–story Alcazar building office in downtown Viña del Mar (Chile). The modeling expands beyond an embedded first story structure to soil with equivalent springs, representing soil–structure interaction (SSI), with varying rigid soil homogeneity. The building was modeled in a finite element software considering only dead load as a static load case because the structure remained in the framing stage when the monitoring system was operating. The instruments registered 72 aftershocks from the 2010 Maule Earthquake, and this study focused on 11 aftershocks of different hypocenters and magnitudes to collect representative information. The comparisons between empirical records and models in this study showed a better fit between the model and the real vibration data for the models that do consider the SSI using horizontal springs attached to the retaining walls of the underground stories. In addition, it was observed that applying a stiffness reduction factor of 0.7 to all elements in deformation verification models for average–height buildings was suitable to analyze the behavior under small earthquakes; better results are obtained embedding the structure in the foundation level than embedding in the street level; the use of horizontal springs with Kuesel’s model with traction for the analysis of the structure yields appropriate results; it is necessary to carefully select the spring constants to be used, paying special attention to the vertical springs. Even though the results presented herein indicate that the use of vertical springs to simulate the SSI of the base slab can result in major differences concerning the real response, it is necessary to obtain more data from instrumentation across a wider variety of structures to continue to evaluate better design and modeling practices. Similarly, further analyses, including nonlinear time–history and high–intensity events, are needed to best regulate building design.

Space Station Environmental, Thermal Control and Life Support (ETCLS): “Meeting the Evolutionary Growth Challenge”

1984 ◽  
Vol 106 (4) ◽  
pp. 287-291
Author(s):  
H. F. Brose
Keyword(s):  
Closed Loop ◽  
Life Support ◽  
Technology Development ◽  
Low Cost ◽  
Space Station ◽  
Thermal Control ◽  
Development Effort ◽  
Program Cost ◽  
Preparedness Plan ◽  
Evolutionary Growth

Renewed interest and planning for a Space Station, probably NASA’s next major space activity, poses a new challenge for ETCLS technology not previously emphasized. Over the past two decades, regenerative life support technology development for Space Station has been underway. This development effort was always aimed at regenerative (closed loop) life support for a full capability Space Station. The level of priority for manned space presence and current budgetary pressures dictate the need for a low cost profile program with an evolutionary growth Space Station. The initial capability may be a small station with a crew of 2 or 3. This station could grow in size and capability by the addition of modules to a station with a crew of 8 to 12 with the possibility of multiple stations in orbit. Depending upon the selected missions, the early station may be best served by an open or only partially closed loop ETCLS whereas the final station may need a completely closed loop ETCLS. The challenge would be to grow in-orbit the ETCLS system capability in a “no-throw-away” fashion in order to minimize annual and total program cost. This paper discusses a possible ETCLS system evolutionary growth scenario, the Space Station architecture variations influencing the ETCLS system design, and a technology preparedness plan for Space Station ETCLS.

NUMERICAL ANALYSIS OF FLOW BEHAVIOR IN GAS-LIQUID CYLINDRICAL CYCLONE (GLCC©*) SEPARATORS WITH INLET DESIGN MODIFICATIONS

2021 ◽  
pp. 1-27
Author(s):  
Srinivas Swaroop Kolla ◽  
Ram S. Mohan ◽  
Ovadia Shoham
Keyword(s):  
Numerical Study ◽  
Flow Behavior ◽  
Low Cost ◽  
Field Application ◽  
Attractive Alternative ◽  
Inlet Section ◽  
Wide Range ◽  
Cylindrical Cyclone ◽  
Light Oil ◽  
Section Design

Abstract The Gas-Liquid Cylindrical Cyclone (GLCC©*) is a simple, compact and low-cost separator, which provides an economically attractive alternative to conventional gravity-based separators over a wide range of applications. More than 6,500 GLCC©'s have been installed in the field to date around the world over the past 2 decades. The GLCC© inlet section design is a key parameter, which is crucial for its performance and proper operation. The flow behavior in the GLCC© body is highly dependent on the fluid velocities generated at the reduced area nozzle inlet. An earlier study (Kolla et al. [1]) recommended design modifications to the inlet section, based on safety and structural robustness. It is important to ensure that these proposed configuration modifications do not adversely affect the flow behavior at the inlet and the overall performance of the GLCC©. This paper presents a numerical study utilizing specific GLCC© field application working under 3 different case studies representing the flow entering the GLCC, separating light oil, steam flooded wells in Minas, Indonesia. Commercially available Computational Fluid Dynamics (CFD) software is utilized to analyze the hydrodynamics of flow with the proposed modifications of the inlet section for GLCC© field applications.

scholarly journals Low Cost Frictional Seismic Base-Isolation of Residential New Masonry Buildings in Developing Countries: A Small Masonry House Case Study

2017 ◽  
Vol 11 (1) ◽  
pp. 1026-1035 ◽  
Author(s):  
Ahmad Basshofi Habieb ◽  
Gabriele Milani ◽  
Tavio Tavio ◽  
Federico Milani
Keyword(s):  
Finite Element ◽  
Seismic Vulnerability ◽  
Base Isolation ◽  
Low Cost ◽  
Element Model ◽  
Shaking Table ◽  
Fe Model ◽  
Isolation System ◽  
Finite Element Software ◽  
Non Linear

Introduction:An advanced Finite Element model is presented to examine the performance of a low-cost friction based-isolation system in reducing the seismic vulnerability of low-class rural housings. This study, which is mainly numerical, adopts as benchmark an experimental investigation on a single story masonry system eventually isolated at the base and tested on a shaking table in India.Methods:Four friction isolation interfaces, namely, marble-marble, marble-high-density polyethylene, marble-rubber sheet, and marble-geosynthetic were involved. Those interfaces differ for the friction coefficient, which was experimentally obtained through the aforementioned research. The FE model adopted here is based on a macroscopic approach for masonry, which is assumed as an isotropic material exhibiting damage and softening. The Concrete damage plasticity (CDP) model, that is available in standard package of ABAQUS finite element software, is used to determine the non-linear behavior of the house under non-linear dynamic excitation.Results and Conclusion:The results of FE analyses show that the utilization of friction isolation systems could much decrease the acceleration response at roof level, with a very good agreement with the experimental data. It is also found that systems with marble-marble and marble-geosynthetic interfaces reduce the roof acceleration up to 50% comparing to the system without isolation. Another interesting result is that there was little damage appearing in systems with frictional isolation during numerical simulations. Meanwhile, a severe state of damage was clearly visible for the system without isolation.

Numerical Study on Energy Dissipation and Hysteretic Behavior of Plate-Reinforced Connections

2011 ◽  
Vol 94-96 ◽  
pp. 668-673
Author(s):  
Yan Wang ◽  
Li Ya Zhang ◽  
Shuang Feng ◽  
Xiang Gao
Keyword(s):  
Energy Dissipation ◽  
Numerical Study ◽  
Plastic Hinge ◽  
Hysteretic Behavior ◽  
Cover Plate ◽  
Finite Element Software ◽  
Panel Zone ◽  
Beam Depth ◽  
Flange Thickness ◽  
Reinforced Plate

14 models of plate-reinforced connections are analyzed by finite element software ANSYS. Failure mode, hysteretic behavior, ductility and energy dissipation capacity are comparatively studied. Results show that plastic hinge formed at the end of the reinforced plate, hysteretic cruves are full and the connections have good ductility. With the increase in length and thickness of the reinforced plate, bearing capacity increases while hysteretic behavior and ductility factor decrease. If the reinforced plate is longer than the length that design requires, brittle failure occurs in the panel zone. The recommended length of the reinforced plate is defined as 0.5-0.8 times of beam depth, the thickness of flange-plate is 1.2-1.4 times of flange thickness and the thickness of cover-plate is 0.7-1.2 times of flange thickness.

scholarly journals A Quadruped Robot with the Wooden Body for Static Locomotion in a Controlled Environment

2020 ◽  
Author(s):  
Muhammad Bilal Khan
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Low Cost ◽  
Control Design ◽  
Quadruped Robot ◽  
Legged Robots ◽  
Controlled Environment ◽  
Robot Design ◽  
Classroom Setting

We present the design and overall development of an eight degrees of freedom (DOF) based Bioinspired Quadruped Robot (BiQR). The robot is designed with a skeleton made of cedar wood. The wooden skeleton is based on exploring the potential of cedar wood to be a choice for legged robots’ design. With a total weight of 1.19 kg, the robot uses eight servo motors that run the position control. Relying on the inverse kinematics, the control design enables the robot to perform the walk gait-based locomotion in a controlled environment. The robot has two main aspects: 1) the initial wooden skeleton development of the robot showing it to be an acceptable choice for robot design, 2) the robot’s applicability as a low-cost legged platform to test the locomotion in a laboratory or a classroom setting.

A Numerical Study on the Thermal Control of Lithium Batteries by Composite Phase Change Materials and Metal Foams

2021 ◽  
Author(s):  
Bernardo Buonomo ◽  
Oronzio Manca ◽  
Ferdinando Menale ◽  
Francesco Moriello ◽  
Simone Mancin
Keyword(s):  
Control System ◽  
Phase Change ◽  
Metal Foam ◽  
Numerical Study ◽  
Liquid Fraction ◽  
Convective Heat Transfer Coefficient ◽  
Thermal Control ◽  
Temperature Fields ◽  
Local Thermal Equilibrium ◽  
Thermal Control System

Abstract This study attempts to control the temperature peaks due to the operation of the battery itself by examining a two-dimensional model to numerically investigate the thermal control of a lithium battery of a commercial electric car. The battery has the dimensions of 8 cm × 31 cm × 67 cm and its capacity is equal to 232 Ah with 5.3 kWh. Thermal control is achieved by means of an internal layer of copper or aluminum foam and phase change material (paraffin), placed on the top of the battery and the external surfaces are cooled by a convective flow. The governing equations, written assuming the local thermal equilibrium for the metal foam, are solved with the finite volume method using the commercial code Ansys-Fluent. Different cases are simulated for different thicknesses of the thermal control system and external convective heat transfer coefficient. The results are given in terms of temperature fields, liquid fraction, surface temperature profiles as a function of time and temperature distributions along the outer surface of the battery for the different cases. In addition, some comparisons with pure PCM are provided to show the advantages of the composite thermal control system with PCM inside the metal foam.

Experimental and numerical study on largely perforated steel shear plates with rectangular tube–shaped links

2020 ◽  
Vol 23 (15) ◽  
pp. 3307-3322 ◽  
Author(s):  
H Monsef Ahmadi ◽  
MR Sheidaii ◽  
H Boudaghi ◽  
G De Matteis
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Equivalent Plastic Strain ◽  
Absorption Capacity ◽  
Hysteretic Behavior ◽  
Steel Plate Shear Wall ◽  
Grid Systems ◽  
Finite Element Software ◽  
Internal Link ◽  
Rectangular Tube

Steel plate shear wall is one of the most effective dissipation systems which are commonly used in buildings. In order to improve the hysteretic behavior of shear panels, large perforation patterns may be applied, transforming the shear plate into a sort of grid systems, where plastic deformations are concentrated on specific internal link elements. This study investigates the behavior of grid systems loaded in shear where the internal links are created by cutting out internal parts, leaving rectangular tube–shaped link elements. The influence of internal link geometry on the cyclic performance of the systems is investigated experimentally. To this purpose, two specimens that varied in the width of links were fabricated and tested. The results indicate that any increase in the width of links leads to the growth of the ultimate strength, stiffness, and energy absorption capacity. Likewise, the stress distribution and fracture tendency of the tested specimens have been simulated by the finite element software (ABAQUS) and validated according to the experimental results. Based on finite element results, a suitable analytical formulation for the prediction of the shear strength at several shear deformation demands, considering the effect of thickness of the link, has been provided. Moreover, to improve the fracture tendency of the specimens, butterfly-shaped links, which varied in the middle length, were applied. The obtained results, which have been interpreted by considering the equivalent plastic strain value, prove that the shear panel behavior improves significantly when butterfly-shaped links are considered.

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