Computational analysis of heat and mass transfer during microwave drying of timber

Abstract

The need for improvement in engineering design and process optimization for microwave drying of wood has stimulated the development of computer simulation techniques to predict temperature and moisture history and distribution wood sample. A 3-D comprehensive heat and mass transfer model was developed to simulate the free liquid, vapor, and bound water movement including consideration of internal heat generation in microwave drying of yellow poplar specimens. The model was solved using the finite element analysis with FEMLAB software. The model predictions compared favorably with predicted and experimental solutions. The effect of changes of the most important parameters on the predictions of the model is also presented. The results showed that the variations of irradiation time, microwave power level and sample thickness played an important role in overall drying kinetics.

Uniform large­sized lumber drying system using mw radiation and basing on a single­wire E00 wave energy transmission line

“…The paper [5] reports a three-dimensional comprehensive heat and mass transfer model developed to simulate the free liquid, vapor, and bound water in microwave drying of yellow poplar specimens.…”

“…The proposed E 00 type surface wave excitation system consists of three half-wave vibrators (1-3), one of which is connected to a coaxial feeder via a quarter-wave locking cup (4). The system formed of three half-wave vibrators is installed near a single wire with a dielectric coating (5). A flat disk-shaped reflector (6) can be installed on one side of such a system.…”

Numerical study of laminar and turbulent flow with radiatively participating media

“…Conjugate heat and mass transfer by natural convection is present in several engineering problems like nuclear reactors, combustion, drying process, solar still devices, electronics devices, thermal comfort, etc [1][2][3][4]. In the last 25 years, the study of conjugate heat transfer with participating media has increased due to the advances in computational technology, especially in those topics of natural convection and radiation [5][6][7][8][9][10] and natural heat and mass transfer convection [11][12][13].…”

Investigation of air jet impingement drying with forced convection of moist things

“…Bir ahşabın mikrodalgada kurutulmasının özellikleri kurutma süreci sırasında gözenekli katı (ahşap) için Lambert' in üç boyutlu kanununu içeren Luikov modeli kullanılarak ve akış alanı için ise üç boyutlu Navier-Stokes denklemleri çözülerek araştırılmıştır. Sonuçlar; ışınlama zamanı, mikrodalga güç seviyesi ve numune kalınlığı değişimlerinin tüm kurutma sürecinde önemli rol oynadıklarını göstermiştir [24]. Benzer olarak bir diğer çalışmada, Femlab paket programı kullanılarak ahşap için üç boyutlu birleştirilmiş ısı ve kütle korunum denklemlerinin sayısal çözümlemesi gerçekleştirilmiştir.…”