Temperature In Different Layers Research Articles

Layer combination design and effect evaluation of phase change cooling asphalt pavement

Asphalt mixture is a temperature sensitive material. With the change of external environment temperature, asphalt pavement is prone to temperature-related diseases. Adding phase change material (PCM) to asphalt pavement to adjust pavement temperature is one of the effective methods at present. At present, there are many types of research on PCMs, but the research on PCMs added to the pavement structure is very scarce. In this paper, through the temperature test of rutting plate specimens with different layer combinations, the cooling effect of pavement structure combinations with PCMs added to different layers (upper layer, middle layer, and bottom layer) in pavement structure under different illumination times are discussed. Through the self-designed environmental simulation box, the real-time monitoring of the temperature of different layers in the pavement structure is realized. The cooling effect between different layers in different phase change pavement structure combinations is analyzed, and compared with each layer of ordinary pavement structure, and the best addition method is obtained for phase change materials, which provides a certain reference for the construction and specific application of PCM asphalt pavement, and made important contributions to the development of asphalt cooling pavement. The results show that the PCM can effectively reduce the temperature of each layer of the pavement structure. Under different illumination durations, the cooling effect of the samples with PCM in the upper layer was the worst. The samples with phase change material in the middle layer had the best cooling effect in the upper and middle layers of the pavement. The addition of phase change material to both the upper and middle layers had the most obvious cooling effect on the lower layer of the pavement. Therefore, combined with the comprehensive consideration of economy and cooling effect, the comprehensive cooling effect of adding PCMs to the middle surface layer is the best. It is recommended to add phase change materials to the middle surface layer during asphalt cooling pavement construction.

Investigation of thermal effect of floor coverings made of nano metal oxide on wastewater temperature and solar pond performance

In this research, the exit treated wastewater from the gravity filtration unit, mechanical and chemical treatment unit, biological treatment unit and finally UV disinfection treatment unit enters to a solar desalination unit. Wastewater evaporation process is performed in this unit. In this study, in order to increase the UV waves in solar energy, nano-flooring has been used on the floor of the solar pond. The laboratory results show that the average difference between the experimental data and the theoretical results for simple coating, coating made of zinc oxide nanoparticles and coating made of aluminum oxide nanoparticles is equal to 2%, 2.3% and 1.6%, respectively. Laboratory results show that the average temperature difference between theory and laboratory when simple coating, nano zinc oxide coating and nano aluminum oxide coating are used are 0.5%, 2.89% and 0.67%, respectively. The laboratory results show that the minimum and maximum average temperature of different layers of wastewater are related to the months of January and July, respectively. This research shows that the maximum and minimum temperature difference of the first layer and the last layer of wastewater are in April and March, respectively.

Research on grain-stored temperature prediction model based on improved SVR algorithm

When using the support vector regression method to predict grain storage temperature, it is challenging to choose the appropriate model parameters. Generally, it is effective to examine the trend of grain storage temperature in different layers after ventilation intervention. To enhance the performance of a support vector machine, it is necessary to choose an appropriate parameter optimization algorithm. The adaptive particle swarm optimization algorithm completes the operation by continuously updating the particles in the spatial domain; after discussing its application principle in detail, the convergence effect is more optimal; and the algorithms are applied to parameter optimization for support vector regression models. After employing the adaptive particle swarm optimization algorithm, the evaluation indicators and experimental prediction results demonstrate that the APSO model has fewer errors, a higher tracking degree, superior generalization performance, and greater prediction accuracy. This is a useful resource for forecasting grain temperature trends.

Spatiotemporal variation characteristics of hourly soil temperature in different layers in the low-latitude plateau of China

Soil temperature change has considerable impact on land surface energy and water balances, and hence on changes in weather/climate, surface/subsurface hydrology, and ecosystems. However, little is known regarding the spatiotemporal variations and influencing factors of changes in hourly soil temperature (depth: 5–320 cm) in low-latitude highland areas. This study analyzed the hourly soil temperature at each hour during 2004–2020 and at 08:00, 14:00, and 20:00 (Beijing Time) during 1961–2020. The results revealed the following. 1) As soil depth increased, average soil temperature increased in autumn and winter, and decreased annually and in spring and summer. It exhibited significant increase during 00:00–23:00 annually, seasonally, and monthly, especially at depths of 40–320 cm during 2004–2020. Average soil temperature increased at 08:00 and decreased at 14:00 and 20:00 with increasing soil depth, but the opposite trend was found annually, seasonally, and monthly at 08:00, 14:00, and 20:00 during 1961–2020. 2) With increasing elevation, average soil temperature decreased at 08:00, 14:00, and 20:00 at depths of 5–20 cm, and showed significant increase trend at 08:00 and 14:00 at depths of 10–20 cm (except at 14:00 at 10-cm depth). 3) At 5-cm depth, the critical accumulated soil temperature of ≥12°C and 14°C extended the potential growing season during 1961–2020. 5) Significant uptrend of hourly soil temperature annually, seasonally, and monthly potentially leads to additional release of carbon to the atmosphere and increased soil respiration, reinforcing climate warming. These findings contribute to better understanding of the variation of shallow soil temperatures and land–atmosphere interactions in low-latitude highland areas.

A thermal resistant and flame retardant separator reinforced by attapulgite for lithium-ion batteries via multilayer coextrusion

Multilayer separators are widely used due to their wide shutdown window by combining lower melting temperature and higher melting temperature of different layers. With the development of high power lithium-ion batteries, multilayer separators equipped with effective thermal stability and flame retardancy are highly required. Herein, the poly(methyl methacrylate) modified attapulgite (ATPM) is selected as the heat resistant reinforcing component and blended with polypropylene (PP)/polyethylene (PE) respectively. Then we prepare PP(ATPM)/PE(ATPM) separators via multilayer coextrusion efficiently without multiple stretching processes, which can avoid serious separator shrinkage at elevated temperature. The intertwined ATPM could not only enhance the separator integrity, but also produce water vapor and oxide anti-flaming isolation layers at high temperatures. The as-prepared separators, referred to as MC-TIPS PP/PE/ATPM, exhibit higher thermal stability (with negligible dimensional shrinkage up to 180 °C), better flame retardancy and wider shutdown temperature window (124–183 °C) than the commercial multilayer separators. Moreover, the introduction of ester and hydroxyl groups could improve the wettability and electrolyte uptake of the separators. These properties, as well as the potential for large-scale production of multilayer coextrusion, make MC-TIPS PP/PE/ATPM an ideal choice for high-power battery separators. • A robust multilayer separator of polypropylene and polyethylene reinforced by poly(methyl methacrylate) modified attapulgite (ATPM) is prepared via multilayer coextrusion without multiple stretching processes, then can avoid serious separator shrinkage at elevated temperature. • The addition of hydrous and heat-resistant ATPM can not only enhance thermal integrity of separator, but also produce water vapor/oxide anti-flaming isolation layers at high temperature, thus improve the flame retardancy of separator. • This preparation method can be extended to fabricate other multilayer separators by choosing other suitable polymeric matrix and reinforce filler (inorganic nanowire/fibre, flame retardant powder, etc).

KINETICS OF HEATING OF CAKE PRODUCTS WITH PUMPKIN SEEDS AND BUCKWHEAT FLOUR

The use of non-traditional raw materials to give flour confectionery new consumer properties and to increase it nutritional and biological value enables a change of the rheological properties of dough semi-finished products and the need to adjust the technological parameters of the production. The purpose of the work is to study the influence of the use of non-traditional raw materials, in particular, pumpkin seeds and buckwheat flour on the kinetics of heating of cake products and to establish rational parameters for baking dough semi-finished products. The change in temperature of the samples during the heat treatment was measured by means of chromel-droplet thermocouples. To measure the temperature of different layers of dough semi-finished products, thermocouples were placed at different height of the dough semi-finished product. The results of the study showed that the use of non-traditional raw materials (pumpkin seeds and buckwheat flour) causes a change in the kinetics of heating of dough semi-finished products. Therefore, this non-traditional raw material affects the processes that occur during the baking of semi-finished dough. A study of cake products with pumpkin seeds and buckwheat flour revealed that they need 3 minutes longer of baking time than products using traditional technology. At the same time, it might be useful to reduce the temperature in the working oven by 5°C to ensure better height formation of the products and to avoid their burning. Thus, a slight increase in baking time will not cause excessive energy consumption. Based on the obtained results, the recommended parameters for baking of cake products with pumpkin seeds and buckwheat flour are determined as the following: baking time – 28 minutes at 205 … 210ºС.

Q-Thermal: A Q-Learning-Based Thermal-Aware Routing Algorithm for 3-D Network On-Chips

The multilayer structure of 3-D network-on-chips (3-D NoC) leads to the unequal thermal conductance between different layers and, as a result, an unbalanced thermal distribution in the chip. This issue leads to the low reliability and performance degradation of 3-D NoCs. To ensure thermal safety, 3-D NoCs require effective cooling methods. Several thermal-aware routing algorithms have been proposed to route packets in a way which helps mitigation of imbalance temperature distribution. To have a thermal-aware path selection and safety thermal distribution, we propose a new thermal-aware routing method based on the Q-learning algorithm (Q-Thermal). In our method, thermal information propagates over the network using ordinary network packets. Thanks to the Q-learning algorithm that keeps always the thermal information of routers up-to-date that causes routers steer packets toward the cooler paths (laterally or vertically). Based on the experimental results, Q-Thermal reduces the heat and temperature of different layers of 3-D NoCs significantly in comparison with the previous state-of-the-art techniques. Q-Thermal leads to a balanced thermal distribution in the stacked layers of the chip and it improves the network performance considerably.

Why heat transfer coefficients are unnecessary and undesirable, and how heat transfer problems are solved without them.

For 200 years, convective heat flux q has been calculated by multiplying heat transfer coefficient h times boundary layer temperature difference T. Since h times T equals q, h must be a symbol for (q/T) because (q/T) times T equals q. h (ie q/T) is generally calculated from correlations derived from experiments in which q data and T data are used to obtain (q/T){T} correlations-ie h{T} correlations. (It is not possible to obtain h data because h is not a parameter. h is the ratio of two parameters). Heat transfer coefficients are unnecessary and undesirable. It is self-evident that any problem that can be solved using q, q/T (ie h), and T can also be solved using only q and T. Therefore h (ie q/T) is unnecessary. h (ie q/T) is undesirable because, when q is a nonlinear function of T (as in free convection, condensation, and boiling), h (ie q/T) is an extraneous variable, and it greatly complicates problem solutions. When h has been abandoned, convective heat flux is determined from q{T} correlations that result from q data and T data, or from the transformation of h{T} correlations. (Transformation from h{T} correlations to q{T} correlations requires that h be replaced by q/T, and that q and T be separated.). The text includes example problems that validate the conclusion that h (ie q/T) is unnecessary and undesirable, and demonstrate that the solution of nonlinear problems is much simpler if h is abandoned.

Experimental and numerical study for effective thermal conductivity of metallic honeycomb sandwich structures

Effective thermal conductivity is an essential parameter to investigate thermal properties of metallic honeycomb sandwich structures. And it cannot be measured by traditional methods due to sandwich structure imbedded with air. A practical experimental equipment was designed to evaluate the value under different temperature from 100°C to 400°C. And it was found that the value of effective thermal conductivity can also be calculated by knowing the thermal conductivity of the reference, thickness of the reference and the slope and intercept of temperature in different layers. Meanwhile, numerical simulation was conducted and the results agreed well with that achieved by experiment. Also, the value of effective thermal conductivity calculated by experiment is close to the value calculated by Swann-Pittman empirical equation. And the method is not limited in metallic honeycomb sandwich structure while it can be applied in most structures with amounts of air. On that basis, heat transfer process of the structure is discussed including heat conduction, heat convection and heat radiation.

A 10-Yr Global Land Surface Reanalysis Interim Dataset (CRA-Interim/Land): Implementation and Preliminary Evaluation

A land surface reanalysis dataset covering the most recent decades is able to provide temporally consistent initial conditions for weather and climate models, and thus is crucial to verifying/improving numerical weather/climate forecasts/predictions. In this paper, we report the development of a 10-yr China Meteorological Administration (CMA) global Land surface ReAnalysis Interim dataset (CRA-Interim/Land; 2007–2016, 6-h intervals, approximately 34-km horizontal resolution). The dataset was produced and evaluated by using the Global Land Data Assimilation System (GLDAS) and NCEP Climate Forecast System Reanalysis (CFSR) global land surface reanalysis datasets, as well as in situ observations in China. The results show that the global spatial patterns and monthly variations of the CRA-Interim/Land, GLDAS, and CFSR climatology are highly consistent, while the soil moisture and temperature values of the CRA-Interim/Land dataset are in between those of the GLDAS and CFSR datasets. Compared with ground observations in China, CRA-Interim/Land soil moisture is comparable to or better than that of GLDAS and CFSR datasets for the 0–10-cm soil layer and has higher correlations and slightly lower root mean square errors (RMSE) for the 10–40-cm soil layer. However, CRA-Interim/Land shows negative biases in 10–40-cm soil moisture in Northeast China and north of central China. For ground temperature and the soil temperature in different layers, CRA-Interim/Land behaves better than the CFSR, especially in East and central China. CRA-Interim/Land has added value over the land components of CRA-Interim due to the introduction of global precipitation observations and improved soil/vegetation parameters. Therefore, this dataset is potentially a critical supplement to the CRA-Interim. Further evaluation of the CRA-Interim/Land, assimilation of near-surface atmospheric forcing variables, and extension of the current dataset to 40 yr (1979–2018) are in progress.

Numerical Study of the Thermal Stability of YBa2Cu3O7- δ Tapes Suffering Lightning Current

In this paper, we presented a numerical model that took into account both the thermal and the electromagnetic aspects to study the thermal stability of YBa 2 Cu 3 O 7-δ (YBCO) tapes suffering lightning current (LC). The electromagnetic and thermal equations have been implemented in finite-element method software in order to obtain a novel homogenization model. The validity of this model was verified by experiment. Based on the model, the distributions of the current and temperature in different layers were presented. The influence of the dimension and material type of different layers on the thermal stability was investigated in detail. The calculated results showed that increasing the width of a YBCO tape and the thicknesses of the encapsulation layer could decrease the maximum temperature. Moreover, the encapsulation layer made of copper is a more desired choice than that made of stainless steel to improve the thermal stability.

An Evaluation of the Performance of Forced Air Cooling on Cooling Parameters in Transient Heat Transfer at Different Layers of Pomegranate

The quality of horticultural products can be promoted using high techniques. One of these methods is precooling applied before storage and leads to increased shelf and storage life of the fruit. For this reason, the effect of forced air cooling was conducted to investigate the cooling rate at the center (aril), spongy tissue (peel) and leathery skin (rind) of pomegranate (Punica granatum L.). Airflow velocity as an effective factor in cooling products at three levels of 0.5, 1, and 1.3 m s-1 and temperature of 7.2 °C was considered. Cooling parameters including lag factor and cooling coefficient were calculated from experimental data. Then, half-cooling time and seven-eighths cooling time were obtained at different layers of pomegranate. Cooling heterogeneity was analyzed at different air velocity and at different layers of pomegranate. The results showed that increase in air velocity from 0.5 to 1.3 m s-1, reduced the half-cooling time and seven-eighths cooling time. After 5000 seconds, the change of air velocity had a slight influence on decreasing temperature of different layers of pomegranate. Cooling heterogeneity at the air velocity of 0.5 m s-1 was low and then increased at the air velocity of 1 m s-1. Finally, at the air velocity of 1.3 m s-1, it was declined. The overall results illustrate that the applied methodology in this research, which explains unsteady heat transfer in the cooling process, can be performed in pomegranate or similarly shaped fruits.

Dynamic modeling and entity validation of a photovoltaic system

We established an entitative photovoltaic (PV) module for measuring the electric power in this study. The generating electric efficiency was calculated according to the electric power. Using the heat transfer mechanism generated during the operation of PV module, thermal energy conservation law and lumped capacitance method were combined with Matlab/Simulink to establish the dynamic model of PV module. The ambient temperature, wind speed, and solar radiation of the environmental factors were the inputs used for predicting the time-varying temperature of different layers inside the module. Based on the solar cell temperature, electric power and electric efficiency could be obtained. The electric power of solar cell declined as the solar cell operating temperature increased. In this study, we used entity module to validate the accuracy of the model. The environmental factors of mounting site were applied to design the backsheet material and to improve the output performance of entity solar module. The PV dynamic model and entity validation showed that electric power and electric efficiency errors are smaller than 1.3%. The PV dynamic model can accurately predict the output performance according to the environmental factors of the site. The PV backsheet was made of glass with higher thermal conductivity to replace traditional tedlar-polyester-tedlar (TPT). Electric power and electric efficiency are increased by 2.353%. The output performance of solar module was improved effectively.

A new soil-temperature module for SWAT application in regions with seasonal snow cover

Summary Accurate estimates of soil temperature are important for quantifying hydrological and biological processes in hydrological models. Soil temperature predictions in the widely used Soil and Water Assessment Tool (SWAT) have large prediction errors when applied to regions with significant snow cover during winter. In this study, a new physically-based soil-temperature module is developed as an alternative to the empirical soil-temperature module currently used in SWAT. The physically-based module ​simulates soil temperature in different soil layers as a result of energy transfer between the atmosphere and soil (or snow) interface. The modified version of SWAT with the new soil-temperature module in place, introduces only three new parameters over the original soil-temperature module. Both the original and new soil-temperature modules are tested against field data from the Black Brook Watershed, a small watershed in Atlantic Canada. The results indicate that both versions of soil-temperature module ​are able to provide acceptable predictions of temperature in different layers of the soil during non-winter seasons. However, the original module severely underestimates soil temperatures in winter (within −10 to −20 °C), while the new module produces results that are more consistent with field measurements (within −2 to 2 °C). In addition, unlike its counterpart, the new module ​is able to simulate freeze–thaw cycles in the soil profile. Ice-water content variations in winter are reasonably simulated by the new module for different snow cover scenarios. In general, modified-SWAT improves prediction accuracy on baseflow discharge compared with the original-SWAT, due to improved estimates of soil temperature during winter. The new physically-based soil-temperature module has greatly improved the ability of SWAT to predict soil temperatures under seasonal snow cover, which is essential to the application of the model in regions like Atlantic Canada.

园林树木增湿降温生态功能评价方法的研究

Nine species of landscape trees cultivated on the campus of Jilin Agricultural University were selected to investigate reasonable sampling positions for evaluating the trees ecological effects in terms of increasing humidity and reducing temperature through leaf area transpiration. The crown of each variety of tree was divided into four layers; surface layer( part A),outer layer( part B),middle layer( part C) and inner layer( part D). The increased humidity and reduced temperature values of unit leaf area caused by transpiration in each layer were determined and compared with different layers within and among species. The results showed that except for the species Juglans mandshurica and Cornus alba,nine tested species all showed the same feature in terms of the capacity to increase humidity and reduce temperature per unit leaf area in four layers: the surface layer( part A) the outer layer( part B) the middle layer( part C) the inner layer( part D). The average values for increase in humidity of the surface layer( A),outer layer( B),middle layer( C) and inner layer( D) in the nine species were 2.87,2.57,2.12 and 1.73 kg m-2d-1respectively,and the average value was 2.32 kg m-2d-1. Compared with the average values,the values of the surface layer( A) and outer layer( B)increased by 23.71% and 10.77% respectively. The values of the middle layer( C) and inner layer( D) decreased by8. 62% and 26.46% respectively. The average values for decrease in temperature in parts A,B,C and D were 0.55,0.50,0. 41 and 0.33℃ respectively,and the average value was 0.45℃. Compared with the average values,the values of the surface layer( A) and outer layer( B) increased by 22.22% and 11.11% respectively. The values of the middle layer( C)and inner layer( D) decreased by 8. 89% and 26. 67% respectively. Among the nine species,the capacity to increase humidity and reduce temperature in arbor life forms was better than that in shrub life forms. For example,the average values for increase in humidity and decrease in temperature in five arbor life forms—Juglans mandshurica,Catalpa ovata,Euonymus bungeanus,Armeniaca mandshurica and Crataegus pinnatifida—were 2.50 kg m-2d-1and 0.49℃ respectively.The average values for increase in humidity and decrease in temperature in the shrub life forms Prunus triloba,Cornus alba,Lonicera ruprechtiana and Hydrangea paniculata were 2. 10 kg m-2d-1and 0. 41℃. The variations in standard deviation( SD) and variable coefficient( VC) among species were larger than those within species. The values of SD within species were between 0. 91( Euonymus bungeanus) and- 0. 23( Lonicera ruprechtiana),and the average value was 0. 54. The values of VC within species were between 0. 47( Euonymus bungeanus) and- 0. 13( Lonicera ruprechtiana),and the average value was 0.26. The values of SD among species were between 1.39( surface layer) and-0.88( inner layer); the average value was 1.07. The values of VC among species were between 0.48( outer layer) and-0.51( inner layer); the average value was 0.47. The variations in the capacity to increase humidity and reduce temperature in different layers of the arbor life forms were larger than those in the shrub life forms. The average SD values of the arbor life forms were 0.64 and0. 12; the average VC value of the arbor life forms was 0.28. The average SD values of the shrub life forms were 0.49 and0. 08; the average VC value of the shrub life forms was 0.23. The result of the study suggests that it is reasonable to select part B or part C near the top of part B as the optimal sampling positions for evaluating the ecological function of landscape trees.

Thermal modeling and analysis of advanced 3D stacked structures

The emerging three-dimensional integrated circuits (3D ICs) offer a promising solution to mitigate the barriers of interconnect scaling in modern systems. It also provides greater design flexibility by allowing heterogeneous integration. However, 3D technology exacerbates the on-chip thermal issues and increases packaging and cooling costs. In this work, a 3D thermal model of a stacked system is developed and thermal analysis is performed in order to analyze different workload conditions using finite element simulations. The steady-state heat transfer analysis on the 3D stacked structure has been performed in order to analyze the effect of variation of die power consumption, with and without hotspots, on temperature in different layers of the stack has been analyzed. We have also investigated the effect of the interaction of hotspots has on peak temperature.

Thermal Structure and Moho Temperature of the Qiongdongnan Basin, Northern Margin of the South China Sea

AbstractCompared with continents, there are less studies on lithospheric thermal structure in oceans or continent‐ocean transition zones. Based on submarine heat flow data and related petrological thermal properties available in the Qiongdongnan Basin, we calculate the constitution of heat flow and deep temperature of different layers along four distinct seismic profiles. The crustal structure in this area is divided into four layers based on latest analysis of P‐wave velocity variation, that is sediment cover. Upper crust, normal lower crust and anomalous lower crust with high velocity, respectively. The results demonstrate that mantle heat flow increases from shallow water to deep water, which predominantly results in the current distribution of submarine heat flow in the Qiongdongnan Basin. Besides, its ratio to submarine heat flow is 76.3±7.0% on average, suggesting a typical feature of the lithospheric thermal structure model consisting of “cold crust and hot mantle”. In addition, Moho temperature beneath the Qiongdongnan Basin concentrates in the range 500~700 °C with a lower temperature region and two higher temperature regions, which is primarily ascribed to the extent of the lithospheric thinning of the northern margin and well‐developed faults of the South China Sea.

Analysis of Vanadium-Bearing Titanomagnetite Sintering Process by Dissection of Sintering Bed

Many problems appear in the sintering process of vanadium-bearing titanomagnetite, such as high energy consumption and low productivity; sinter quality is also very poor for its low tumble strength and high reduction degradation. Sinter productivity and quality are dominated by bed permeability and mineralogy structure, which are highly influenced by the thermal state of sintering bed, so the sintering process of titanomagnetite is researched by bed dissection in this work. Temperature evolution curves of sinter materials were measured, and the results show that melting duration, peak temperature duration and sintering temperature of different layers differ greatly from each other; flame front speed and vertical sintering speed of bed lower region are much smaller than those of bed upper region. Simultaneously, sinter samples were collected from different layers, and their mineralogy characteristics are analyzed; sinters from bed lower region have poor mineralogy structure, and the amounts of perovskite and dicalcium silicate increase intensively, which are bad for sinter strength and reduction degradation property. Measures are proposed to improve the quality and productivity of titanomagnetite sinter.

Mixed Layer Convective Turbulence Theory with First International Satellite‐Land Surface Climatology Project Field Experiment Data

The convective turbulence theory (CTT) [Stull, 1994] has several advantages over traditional bulk atmospheric boundary layer similarity formulations for the surface momentum and sensible heat fluxes under free convection. In particular, in CTT surface fluxes at scales of 101–102 km are parameterized directly from surface and mixed layer measurements, without regard to the surface layer profiles or surface roughness. The equations of CTT are tested with the First International Satellite‐Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) data set; the theory is extended so that geostrophic winds may be used in place of mixed layer winds; the formulation is applied to satellite‐derived surface temperature data; and Stull's [1994] mixed convection interpolation formula is tested. The scatter on graphs of the mixed layer transfer coefficients for momentum and sensible heat is greater for the FIFE data than for the Boundary‐Layer Experiment 1983 (BLX83) data used by Stull [1994], and the mean coefficient values are greater, probably because of the use of radiosonde data at FIFE and spatially averaged aircraft data at BLX83. Surface momentum and sensible heat flux estimated on the basis of CTT produced reasonable results but provided little or no improvement over a direct correlation between the reference fluxes and the mixed layer wind speed or the surface‐to‐mixed layer temperature difference. The geostrophic version of CTT provided results comparable to the original CTT. Remotely sensed surface temperatures used with geostrophic CTT allowed reasonable estimates of the surface sensible heat flux.

Kinetics of intense evaporative mass transfer through a porous layer

A kinetic problem of mass transfer in a model porous body in the process of intense evaporation (condensation) and vapour escape into a vacuum is considered. Two computational methods have been used: the mean free path method and the method of direct statistical simulation. With the aid of the first method the location of the condensation zone within a porous body is determined as a function of the evaporating surface-to-porous layer temperature difference and also of the condensation coefficient. The second method is employed in a one-dimensional case to obtain (without condensation) the density, velocity and temperature distributions for a gas in a porous layer and in a gas medium behind the porous body. It is shown that the agreement between the parameters obtained by both methods for the gas flow escaping the porous layer is quite satisfactory