scholarly journals Analytical Investigations of Kinetic and Heat Transfer in Slow Pyrolysis of a Biomass Particle

2013 ◽  
Vol 2 (2) ◽  
pp. 105-115
Author(s):  
S.J Ojolo ◽  
C.A. Osheku ◽  
M.G Sobamowo
Keyword(s):  
Heat Transfer ◽  
Analytical Solutions ◽  
Experimental Results ◽  
Analytical Models ◽  
Thermochemical Conversion ◽  
Percentage Error ◽  
Slow Pyrolysis ◽  
Average Percentage ◽  
Transfer Equations ◽  
Standard Deviations

The utilization of biomass for heat and power generation has aroused the interest of most researchers especially those of energy .In converting solid fuel to a usable form of energy,pyrolysis plays an integral role. Understanding this very important phenomenon in the thermochemical conversion processes and representing it with appropriate mathematical models is vital in the design of pyrolysis reactors and biomass gasifiers. Therefore, this study presents analytical solutions to the kinetic and the heat transfer equations that describe the slow pyrolysis of a biomass particle. The effects of Biot number, temperature and residence time on biomass particle decomposition were studied. The results from the proposed analytical models are in good agreement with the reported experimental results. The developed analytical solutions to the heat transfer equations which have been stated to be “analytically involved” showed average percentageerror and standard deviations 0.439 and 0.103 from the experimental results respectively as compared with previous model in literature which gives average percentage error and standard deviations 0.75 and 0.106 from the experimental results respectively. This work is of great importance in the design of some pyrolysis reactors/units and in the optimal design of the biomass gasifiers.

Actuation and dynamic mechanical characteristics of a core free flat dielectric electro-active polymer soft actuator

2020 ◽  
Vol 14 (4) ◽  
pp. 7396-7404
Author(s):  
Abdul Malek Abdul Wahab ◽  
Emiliano Rustighi ◽  
Zainudin A.
Keyword(s):  
Theoretical Model ◽  
Resonance Frequency ◽  
Dynamic Testing ◽  
Experimental Results ◽  
Percentage Error ◽  
Initial Tension ◽  
Average Percentage ◽  
Soft Actuator ◽  
Average Percentage Error ◽  
Mechanical Dynamics

Various complex shapes of dielectric electro-active polymer (DEAP) actuator have been promoted for several types of applications. In this study, the actuation and mechanical dynamics characteristics of a new core free flat DEAP soft actuator were investigated. This actuator was developed by Danfoss PolyPower. DC voltage of up to 2000 V was supplied for identifying the actuation characteristics of the actuator and compare with the existing formula. The operational frequency of the actuator was determined by dynamic testing. Then, the soft actuator has been modelled as a uniform bar rigidly fixed at one end and attached to mass at another end. Results from the theoretical model were compared with the experimental results. It was found that the deformation of the current actuator was quadratic proportional to the voltage supplied. It was found that experimental results and theory were not in good agreement for low and high voltage with average percentage error are 104% and 20.7%, respectively. The resonance frequency of the actuator was near 14 Hz. Mass of load added, inhomogeneity and initial tension significantly affected the resonance frequency of the soft actuator. The experimental results were consistent with the theoretical model at zero load. However, due to inhomogeneity, the frequency response function’s plot underlines a poor prediction where the theoretical calculation was far from experimental results as values of load increasing with the average percentage error 15.7%. Hence, it shows the proposed analytical procedure not suitable to provide accurate natural frequency for the DEAP soft actuator.

scholarly journals A review of modern numerical and analytical models of heat transfer in a dielectric layer during melting due to microwave radiation

2021 ◽  
Vol 2119 (1) ◽  
pp. 012074
Author(s):  
V A Karelin ◽  
Vl V Salomatov
Keyword(s):  
Heat Transfer ◽  
Microwave Radiation ◽  
Maxwell Equation ◽  
Analytical Solutions ◽  
Dielectric Layer ◽  
Parametric Analysis ◽  
Microwave Field ◽  
Source Term ◽  
Analytical Models

Abstract In this work, numerical and analytical solutions of heat transfer in a dielectric layer during melting in the microwave field were considered. We considered solutions, where the source term was obtained based on the solution of Maxwell equation, as well as using the Lambert law. The conditions applicable for analytical solutions, allowing the parametric analysis, are determined. The areas of application of the technology of microwave melting of dielectrics, in particular with melting ice on water, defrosting products, etc., were also considered.

Modeling of heat transfer for a wet multi-plate clutch based on empirical data

2017 ◽  
Vol 232 (12) ◽  
pp. 1634-1647
Author(s):  
SC Kim ◽  
SB Shim
Keyword(s):  
Heat Transfer ◽  
Empirical Data ◽  
System Analysis ◽  
Experimental Results ◽  
Design Parameters ◽  
Percentage Error ◽  
Inlet Temperature ◽  
Transfer Model ◽  
Validation Parameters ◽  
Wet Clutch

A heat transfer model of a wet multi-plate clutch based on empirical data is presented in this paper. Lumped system analysis was used to simplify the complex heat transfer system of the wet clutch. The model has included the effects of various design parameters of the wet clutch, such as rotating speed, flow rate and inlet temperature of the lubricant, clutch sizes, and groove types, by using the correlations of the heat convection coefficient. The correlations were obtained from 96 experiments that were designed to study the effects of the design parameters. The coefficients of the correlations were determined by the non-dominated sorting genetic algorithm (NSGA-II) to minimize errors between the simulated and the experimental results. The simulated results were compared with the experimental results to demonstrate the validity of the model and the correlations by using the percentage error, the root-mean-square error, and the correlation coefficient. The validation parameters were in good agreement with the experimental results.

Thermal Modeling Applied to Animal Systems

1966 ◽  
Vol 88 (1) ◽  
pp. 125-130 ◽  
Author(s):  
Richard C. Birkebak ◽  
Clifford J. Cremers ◽  
Eugene A. LeFebvre
Keyword(s):  
Heat Transfer ◽  
Heat Loss ◽  
Air Temperature ◽  
Environmental Conditions ◽  
Thermal Modeling ◽  
Experimental Results ◽  
Modeling Approach ◽  
Transfer Equations ◽  
Modeling Techniques ◽  
Environmental Air

Predictions of the heat loss from animal systems under the influence of environmental air temperature using thermal modeling techniques are found to agree with available experimental results. To perform the necessary experiments on heat loss, over a variety of environmental conditions for all species of interest, would be a formidable task. The thermal modeling approach circumvents these difficulties by the use of basic heat-transfer equations and properties and is suggested and exemplified as an alternative.

Thermocapillary Actuation and Cycling of Liquid Plugs

2008 ◽  
Author(s):  
Zhenjun Jiao ◽  
Nam-Trung Nguyen ◽  
Xiaoyang Huang
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Deoxyribonucleic Acid ◽  
Coupling Effect ◽  
Ccd Camera ◽  
Temperature Cycling ◽  
Experimental Results ◽  
Analytical Models ◽  
Chain Reaction ◽  
Polymerase Chain

With the aim toward realizing polymerase chain reaction (PCR) of deoxyribonucleic acid (DNA) in plug-based capillary platforms, this paper reports the theoretical and experimental results of thermocapillary actuation for temperature cycling with an arbitrary ramping function. Two concepts were investigated: (a) actuation and spatial temperature cycling with three heaters and (b) actuation and temporal cycling with two heaters. The paper first describes the analytical models of both concepts. The model considers both the transient and coupling effect between heat transfer in the capillary wall and the surface tension driven movement of the plug. In the experiments, both temperature field and plug motion were measured and evaluated. The temperature field were captured by an infrared thermo tracer camera. The position of the plugs was automatically captured and evaluated with a CCD camera. Finally, analytical and experimental results are compared and discussed.

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