scholarly journals Numerical simulation to evaluate the influence of geometric parameters on the physical behavior of heat exchangers

2021 ◽  
Vol 2139 (1) ◽  
pp. 012006
Author(s):  
J P Rojas Suárez ◽  
J A Pabón León ◽  
M S Orjuela Abril
Keyword(s):  
Numerical Simulation ◽  
Heat Exchangers ◽  
Test Bench ◽  
Electrical Power ◽  
Experimental Tests ◽  
Geometric Parameters ◽  
Engine Test Bench ◽  
High Concordance ◽  
Considerable Impact ◽  
Load Conditions

Abstract In the present investigation, a methodology was developed by means of numerical simulation for the evaluation of the influence of the geometric parameters of the heat exchangers used in thermoelectric generation devices. The validation of the proposed methodology was carried out through experimental tests on a diesel engine test bench under four load conditions (2 Nm, 4 Nm, 6 Nm, and 8 Nm) and a constant speed of 3600 rpm. The results obtained show that the methodology proposed by means of the numerical simulation presents a high concordance with the behavior described experimentally. The deviation between the simulation predictions and the experimental results was less than 4%. Additionally, it was evidenced that the change in the geometry of the heat exchanger has a considerable impact on the parameters of heat flow and surface temperature. It was shown that a 50% reduction in fin distance causes an increase of 2% and 2.4% in the previous parameters. Through geometric modifications, the electrical power generated increased by 7.9%. In general, the methodology developed through numerical simulation allows the analysis of the physical, thermal, and hydraulic phenomena present in heat exchangers focused on use in thermoelectric devices.

Analysis of the thermal variations in a moving pantograph strip using an electro-thermal simulation tool and validating by experimental tests

2019 ◽  
Vol 234 (8) ◽  
pp. 859-868
Author(s):  
Nicolas Delcey ◽  
Philippe Baucour ◽  
Didier Chamagne ◽  
Geneviève Wimmer ◽  
Giuseppe Bucca ◽  
...  
Keyword(s):  
Test Bench ◽  
Electrical Power ◽  
Computation Time ◽  
Experimental Tests ◽  
Simulation Tool ◽  
Heat Sources ◽  
Train Operation ◽  
Catenary System ◽  
Experimental Values ◽  
Physical Phenomena

The performance of the pantograph–catenary system is very significant in supplying reliable electrical power for the operation of trains. Many problems arise due to the increase in temperature inside the pantograph strip. More research works have been done to study the temperature extrema of the system but it is quite difficult to obtain the experimental values during a real-time train operation. Moreover, performing experimental tests needs a representative test bench of the system or a real train. This is challenging owing to the time and availability of materials and taking into account the number of physical phenomena to control and measure. To address this problem, the authors of this study present an electro-thermal modeling tool. The heat sources which characterize the system are analyzed to generate a heat equation formulation. This equation is solved with the finite differences numerical method in order to obtain the temperature distribution in the pantograph strip. In addition, some specifications such as computation time or required memory are taken into account. More precisely, mathematical and numerical optimizations are proposed to improve these specifications. The tool is validated by comparing the simulated results with the experimental tests obtained from a test bench located at POLIMI (Polytechnico Di Milano, Milan). Finally, thermal interpretations as well as relative gap analyses are done in different situations.

Optimal Configuration Selection Through Experimental Tests on Branched Heat Exchanger With R134 Organic Fluid

2019 ◽  
Author(s):  
Roberto Capata ◽  
Alfonso Calabria
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Test Bench ◽  
Experimental Tests ◽  
Constructal Theory ◽  
Detailed Knowledge ◽  
Nusselt Numbers ◽  
Configuration Selection ◽  
Efflux Velocity ◽  
Made In

Abstract The aim of this work the analysis of compact branched heat exchangers, by measuring thermal efficiency and the pressure drop in several experimental tests. Three different heat exchanger configuration have been considered. In the first device, the constant efflux velocity, in the internal channels, was imposed. The second exchanger was realized by imposing constant the value of the Reynolds number. The last device was created according to the instructions of the constructal theory. All three exchangers are aluminum made. In addition, in order to have a more detailed knowledge of the phenomenon and to identify what are the parameters that govern heat transfer, an organic fluid has been used and tested. In our case R1234 organic fluid. It was therefore necessary to realize an appropriate test bench for the use of the organic fluid. Once realized, several tests were conducted. Finally in order to be able to indicate which configuration results the optimal one, the Prandtl and Nusselt numbers were obtained and compared.

scholarly journals Passive Measurement of Three Optical Beacon Coordinates Using a Simultaneous Method

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5235
Author(s):  
Jiri Nemecek ◽  
Martin Polasek
Keyword(s):  
Mathematical Model ◽  
Relative Position ◽  
Experimental Tests ◽  
Image Sensor ◽  
Geometric Parameters ◽  
Light Sources ◽  
Feature Points ◽  
Passive Measurement ◽  
The Mathematical Model ◽  
Physical Principles

Among other things, passive methods based on the processing of images of feature points or beacons captured by an image sensor are used to measure the relative position of objects. At least two cameras usually have to be used to obtain the required information, or the cameras are combined with other sensors working on different physical principles. This paper describes the principle of passively measuring three position coordinates of an optical beacon using a simultaneous method and presents the results of corresponding experimental tests. The beacon is represented by an artificial geometric structure, consisting of several semiconductor light sources. The sources are suitably arranged to allow, all from one camera, passive measurement of the distance, two position angles, the azimuth, and the beacon elevation. The mathematical model of this method consists of working equations containing measured coordinates, geometric parameters of the beacon, and geometric parameters of the beacon image captured by the camera. All the results of these experimental tests are presented.

scholarly journals Assessment of an electrical coolant pump on a heavy-duty diesel engine

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Markus Kiesenhofer
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Carbon Dioxide Emissions ◽  
Test Bench ◽  
Engine Test ◽  
The European Union ◽  
Engine Test Bench ◽  
Commercial Vehicles ◽  
Coolant Pump ◽  
Vehicle Class

AbstractHybridization of the drive train in commercial vehicles is a key solution toward meeting the strict future requirements to reduce carbon dioxide emissions within the European Union. In order to decrease fleet consumption a large number of different hybrid systems are already available in series in the passenger car sector. Due to the cheap and powerful 48 volt hybrid components and the lower hazard potential compared to high voltage, future commercial vehicles could also benefit from the 48V technology and contribute to lower fleet fuel consumption. Therefore, a complete 48V mild hybrid system was built on the diesel engine test bench as part of a research project. This paper highlights the utilization of a powerful 48V-motor to propel the coolant pump on a diesel engine of the 13-L commercial vehicle class. Three different drive variants of the coolant pump were implemented and measured on the diesel engine test bench. MATLAB®/Simulink®-simulations were conducted to assess the possible fuel savings in three different driving cycles. This paper provides a summary and interpretation of the measurement and simulation results. The simulation studies predict a decrease of fuel consumption of up to 0.94%. Furthermore, the additional advantages of electrified coolant pumps based on 48V are discussed.

Experimental Research on Diesel Engine Friction and Wear Based on Ferrographic Analysis

2015 ◽  
Vol 778 ◽  
pp. 195-198 ◽  
Author(s):  
Hai Bing Xiao
Keyword(s):  
Diesel Engine ◽  
Wear Mechanism ◽  
Friction And Wear ◽  
Test Bench ◽  
Particle Morphology ◽  
Wear Particle ◽  
Engine Test Bench ◽  
Experimental Scheme ◽  
Wear Monitoring ◽  
Engine Friction

This paper deals with the study of diesel engine friction and wear. The friction and wear mechanism of diesel engine was studied and the wear factors of diesel engine friction and wear was analyzed. According to the diesel engine test bench, diesel engine experimental scheme of oil testing was designed during running-in stage. Studies have shown that wear particle morphology of diesel engine from ferrographic analysis can reflect the degree of wear and wear mechanism during running-in stage, wear particle changed during running-in stage. Ferrographic monitoring is an effective method for diesel engine friction and wear monitoring.

A modified approach for numerical simulation of capillary tube-suction line heat exchangers

2016 ◽  
Vol 102 ◽  
pp. 283-292 ◽  
Author(s):  
Matheus dos Santos Guzella ◽  
Luben Cabezas-Gómez ◽  
Luiz Gustavo Monteiro Guimarães ◽  
Cristiano Bigonha Tibiriçá
Keyword(s):  
Numerical Simulation ◽  
Heat Exchangers ◽  
Capillary Tube ◽  
Suction Line ◽  
Tube Suction

scholarly journals Numerical simulation of gas-solid flow in an interconnected fluidized bed

2015 ◽  
Vol 19 (1) ◽  
pp. 317-328 ◽  
Author(s):  
Giuseppe Canneto ◽  
Cesare Freda ◽  
Giacobbe Braccio
Keyword(s):  
Numerical Simulation ◽  
Fluidized Bed ◽  
Experimental Tests ◽  
Solid Particles ◽  
Multiphase Model ◽  
Cold Model ◽  
Conservation Equations ◽  
Solid Flow

The gas-particles flow in an interconnected bubbling fluidized cold model is simulated using a commercial CFD package by Ansys. Conservation equations of mass and momentum are solved using the Eulerian granular multiphase model. Bubbles formation and their paths are analyzed to investigate the behaviour of the bed at different gas velocities. Experimental tests, carried out by the cold model, are compared with simulation runs to study the fluidization quality and to estimate the circulation of solid particles in the bed.

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