Vapor Transfer Research Articles

Synergistic effect of screen-printed Al(OH)3 nanoparticles and phosphorylated cellulose nanofibrils on the thermophysiological comfort and high-intensive heat protection properties of flame-retardant fabric

Al(OH)3 nanoparticles (ATH NPs) and phosphorylated cellulose nanofibrils (PCNFs) were used as user-friendly and comfortable coating components on flame-retardant fabric to improve its thermophysiological comfort and high-intensive heat protection properties. The effect of the PCNF imprinting and its attachment after the post-printing of a hydrophobic polyacrylate (AP) on the same (back side) or the other (front) side of the fabric, with and without the addition of ATH NPs, was considered, to maintain the front side (facing the wearer) as hydrophilic while keeping the back side (facing the outside) hydrophobic. The amount of coatings applied and their patterning were studied, varied with the ATH NPs’ concentration (1.7, 3.3 and 6.7 wt%) and screen mesh size used (60 and 135), based on the coating’ mass, fabric’s air permeability, thickness and microstructure. The reduced moisture build-up (55%), increased the water vapour (13%) and heat (12%) transfer from the skin, were assessed by applying PCNF under the AP, being more pronounced in the case of using a 135 mesh-sized screen, given the smaller, more densely distributed, thinner and imprinted pattern coatings. These effects were further improved by the addition of nanoporous ATH NPs, which allowed more homogeneous spreading of the moisture and its faster transport. Such a treatment also shifted the fabric’s degradation temperature towards higher values (up to 15°C), retained up to 30% of high-heat flux (21 kW/m2), prolonged the time to ignition by 11 s and reduced the total heat released by up to 60%, thereby providing better protection when exposed to the heat, due to the presence of the phosphorous (PCNF) promoted generation of an Al2O3 char acting as a barrier layer, while also reducing the production of heat and generation of smoke by 75%.

Performance assessment of a flat-sheet membrane-based dehumidifier with serpentine flow channels: An experimental study

Membrane-based dehumidification system is an emerging technology which drives based on the renewable low-grade energy sources. Water vapor selective membrane is able to separate water vapor from the air which can be used to condition air in buildings, more efficiently than conventional air-conditioning equipment. Flow channel designs (especially serpentine-type) and their impacts on the thermal–hydraulic performance of membrane-based dehumidifiers are essential and not well-studied. In the present work, a novel flat-sheet membrane dehumidifier with serpentine flow channels is designed and evaluated experimentally. The serpentine flow channel offers a long flow path that the air in the wet and dry sides of the channel interacts with each other through the membrane, thereby improving the heat and water vapor transfer. The effect of inlet air flow rate, relative humidity, and temperature of both wet and dry sides on the dehumidification rate, approach temperature, pressure drop, and coefficient of performance of the dehumidifier is examined. Results show that passing the humid air with higher flow rate, humidity, and temperature through the wet side channel leads to the higher dehumidification rate, approach temperature, and pressure drop. Increase of wet side air temperature and flow rate enhances the coefficient of performance, and the effect of inlet air relative humidity on the coefficient of performance is observed negligible at high air flow rates. Parametric study of dry side air condition reveals that the air with lower humidity improves the dehumidification rate and coefficient of performance, while its effect on the approach temperature and pressure drop is observed negligible. Elevated air temperature of dry side has positive and negative impact on the approach temperature and coefficient of performance of the dehumidifier, respectively.

Comfort related woven fabric transmission properties made of cotton and nylon

The interaction of water and air i.e. moisture regain, water vapor transmission, wicking and air permeability with woven textiles are tested to investigate the comfort of woven fabrics made of nylon, cotton, and cotton–nylon mixtures with different yarn counts. The fabrics porosity (based on equation 1 and 2), woven fabric sett (ASTM D3775-03), fabric thickness (ASTM D1777-96), fabric weight (ASTM D3776M - 20), fabric vapour transmission (ASTM E96-00), transfer wicking, and longitudinal wicking (DIN 53924), moisture regain (ASTM D2495-07), and air permeability (ASTM D737) were examined for investigations based on the standards in the brackets. The experimental results showed that fabric transfer wicking, longitudinal wicking, moisture regain and air permeability properties increase as the yarn goes to coarser for all woven fabric samples but the water vapor transmission property decrease. Additionally, fabric transfer and longitudinal wicking capabilities improved with increased nylon fiber blend ratios within fiber conformation. However, the nylon fiber composition has negative impact on air permeability, water vapor transfer rate, wicking and moisture capabilities of the woven fabrics. Generally, it can be concluded that the existence of nylon fiber, and yarn count coarseness improved wicking properties of the woven fabrics and decreased the air permeability property of woven fabrics.

Pressure- and temperature-initiated adsorption of water vapour in a finned flat-tube adsorber

Adsorption heat transformation is an environmentally friendly and effective method of using low-temperature heat from renewable, industrial and domestic sources. The transformation can be initiated by changing either adsorptive pressure (pressure-initiated, PI) or adsorbent temperature (temperature-initiated, TI). This work aims to elucidate how the initiation pathway affects the dynamics of water adsorption for silicoaluminophosphate AQSOA-FAM-Z02 loaded inside a commercial finned flat-tube heat exchanger. The main findings of this study are as follows: (a) all kinetic curves can be represented as a superposition of fast and slow exponentials associated with the process rate limitation by vapour transfer or heat transfer, respectively; (b) at a short time (<150–200 s), the PI adsorption is faster than the TI one by a factor of 3; (c) at a long time (>100–150 s), the PI desorption is slower than the TI one. From the practical point of view, the revealed differences between the PI and TI dynamics could allow the specific power of adsorption heat transformers to be improved through a better organization of the working cycle.

The Impacts of Hydrometeors and Water Vapor in Stratiform Region on the Evolutions of MCSs and Embedded Convective Cells in a Pre‐Summer Rainfall Event Over South China

AbstractBoth the stratiform and convective regions play important roles in the development of mesoscale convective systems (MCSs). In this study, the impacts of hydrometeors and water vapor in stratiform region on the evolution of MCSs during a heavy rainfall event over South China are investigated by the Weather Research and Forecasting (WRF) model with Thompson microphysics. A series of sensitivity experiments including the reductions of water vapor to 95%, 80% (water vapor sensitivity experiments), and the reductions of hydrometeor mixing ratios to 10% (hydrometeor sensitivity experiments) in stratiform region are conducted, respectively. Results show that the control run reasonably reproduces the spatial distribution and temporal evolution of convective rainbands. The hydrometeor flux convergence partly indicates the changes of convection organization and movement direction. The intensities of precipitation and MCSs are significantly weakened by decreasing moisture advection to convective region in water vapor sensitivity experiments, but are a little weaker in hydrometeor sensitivity experiments. The enhanced water vapor advection and reduced sedimentation and evaporation of rain water in hydrometeor sensitivity experiments are responsible for the restoration of stratiform cloud. The stratiform region with more hydrometeors is generally more conducive to the development of convection than less one when they are at the same evolution stage. However, it is found that stronger convective cell can also exist in the stratiform region with less hydrometeors that is generated by the old convection cloud and at its dissipating stage, owing to the more transfer of water vapor and hydrometeors from stratiform to convective regions.

Cavitation Erosion Modelling on a Radial Divergent Test Section Using RANS

Cavitation is the phenomenon of fluid evaporation in hydraulic systems, which occurs due to a pressure drop below the value of the vapor pressure. For numerical modeling of this generally undesirable phenomenon, which is often associated with material damage (erosion), there are various mathematical vapor transfer models that have been validated in the past. There are different approaches to predicting cavitation erosion, which have mostly been experimental in the past. Recently various numerical models have been developed with the development of numerical simulations. They describe the phenomenon of cavitation erosion based on different theoretical considerations, such as Pressure wave hypothesis, Microjet hypothesis, or a combination of both. In the present paper, an analysis of the Schnerr-Sauer transport cavitation model was used, upgraded with an erosive potential energy model based on pressure wave hypothesis for cavitation erosion prediction. The extended numerical model has been applied to the case of a radial divergent test section in three different mathematical formulations. The results of simulation were compared and validated to experimental work performed by other authors. The study shows that the distribution of surface accumulated energy agrees with the experimental results, although certain differences exist between formulations. The applied method appears to be appropriate for further use, and to be extended to materials response modeling in the future.

Intra-Seasonal and Intra-Annual Variation of the Latent Heat Flux Transfer Coefficient for a Freshwater Lake

In the case of lakes, evaporation is one of the most significant losses of water and energy. Based on high-frequency eddy-covariance (EC) measurements between May and September of 2019, the offshore heat and water vapor exchanges are evaluated for the large (~600 km2) but shallow (~3.2 m deep) Lake Balaton (Transdanubian region, Hungary). The role of local driving forces of evaporation in different time scales (from 20 min to one month) is explored, such as water surface and air temperatures, humidity, atmospheric stability, net radiation, and energy budget components. EC-derived water vapor roughness lengths and transfer coefficients (Cq) show an apparent intra-seasonal variation. Different energy balance-based evaporation estimation methods (such as the Priestley-Taylor and the Penman-Monteith) confirm this observation. Furthermore, this has suggested the existence of an intra-annual variation in these parameters. This hypothesis is verified using ten years of water balance measurements, from which, as a first step, evaporation rates and, second, transfer coefficients are derived on a monthly scale. Cq is highly reduced in winter months (~1 × 10−3) compared to summer months (~2.5 × 10−3) and strongly correlated with net radiation. The application of time-varying Cq significantly increases the accuracy of evaporation estimation when the Monin-Obukhov similarity theory-based aerodynamic method is applied. The determination coefficient increases to 0.84 compared to 0.52 when a constant Cq is employed.

Noninvasive refilling of liquid marbles with water for microfluidic applications

Liquid marbles, liquid droplets coated with hydrophobic powder, have been emerging as a useful microfluidic platform. The ease of their synthesis and manipulation allows liquid marbles to serve as a robust microreactor. However, liquid marbles suffer the unavoidable problem of evaporation. Exposed to an environment with relatively low humidity, the liquid marble buckles and collapses due to evaporation. A suitably noninvasive technique to refill the liquid marble with water may open better opportunities for liquid marbles in microfluidics. To date, there has been no report on noninvasive methods for refilling the deflated liquid marble after the evaporation and subsequent buckling. This paper reports the noninvasive automatic refilling of liquid marbles using the concept of vapor transfer through porous media and subsequent condensation.

Inference of Parameters for a Global Hydrological Model: Identifiability and Predictive Uncertainties of Climate‐Based Parameters

AbstractCalibration of global hydrological models (GHMs) has been attempted for over two decades; however, an effective and generic calibration method has not been explored. We present a novel framework for calibrating GHMs assuming that parameters can be regionalized by climate similarities. We calibrated four sensitive parameters of the H08 global hydrological model by aggregating the results of 5,000 simulations with randomly generated parameters into 11 Köppen climate classes and using an objective function Nash–Sutcliffe Efficiency (NSE) with random sampling from the proposed parameter distribution. From a 100‐fold split‐sampling test, we found that both the representativeness and robustness of the transferred parameter sets were guaranteed when the upper 5% of the samples were accepted and assign the median of each accepted parameter distribution for the climate class. The simulation with the climate‐based parameters yielded satisfactory (NSE &gt; 0.0) and good (NSE &gt; 0.5) performances at 480 and 234 stations (61.7% and 30.1% of 777 stations), respectively. The storage capacity (SD) and the conductive coefficient (CD) were sensitive to the climate classes and exhibited well‐constrained distributions of the accepted samples, whereas the recession parameters for the subsurface storage (γ and τ) showed little or no explanatory power to climate. The identified parameters for climate classes exhibited consistency with the physical interpretation of soil formation and efficiencies in vapor transfer. The consistency of the identified parameter values with physical underpinnings indicates that the appropriate parameters were determined, which ensured the robustness of parameters, especially when they are transferred to ungauged watersheds.

Modeling vapor transfer in soil water and heat simulations: A modularized, partially-coupled approach

Coupled water and heat transfer models are widely used to analyze soil water content and temperature dynamics, evaluate agricultural management systems, and support crop growth modelling. In relatively dry soils, vapor transfer, rather than liquid water flux, becomes the main pathway for water redistribution. However, in some modularized soil simulators, e.g., 2DSOIL (Timlin et al., 1996), vapor transfer is not included, which may induce errors in soil water and heat modelling. Directly embedding vapor transfer into existing water and heat transfer modules may violate the modularized architecture of those simulators. Therefore, the objectives of this study are to design a vapor transfer model, evaluate its performance, and implement it as a separate module in a coupled soil water and heat simulator, e.g., 2DSOIL. The efficacy of the vapor transfer model is evaluated by comparing the simulated soil water content and temperature before and after including the new vapor transfer model, and the soil water content and temperature simulated with the standard Philip and de Vries (1957) model. By implementing vapor transfer as a separate module in 2DSOIL, modifications to existing water and heat transfer modules can be minimized and the modularized model architecture can be maintained. Numerical examples of 2DSOIL with the new vapor transfer model are presented to illustrate the effects of vapor flux on soil water and temperature redistributions. In conclusion, the new vapor transfer model provides an effective and easy-to-use method to account for the effects of vapor transfer on coupled soil water and heat simulations.

Investigation of coupled vapor and heat transport in hygroscopic material during adsorption and desorption

Vapor sorption in hygroscopic porous materials is accompanied by latent heat release/storage, which can influence indoor thermal comfort and building heating and cooling energy consumption. There is a need to better understand the coupled vapor and heat transport during adsorption and desorption. In this study, longitudinal spruce samples are exposed to adsorption and desorption experiments. Neutron radiography provides accurate measurement of moisture content variations spatially and temporally. Wireless thermocouples provide accurate measurements of temperature at different locations. Large changes in moisture content and temperature are observed during both adsorption and desorption experiments. Both moisture content and temperature variations seen in experiments are well simulated with hygrothermal modeling. The latent heat associated with vapor sorption is found to be the source of the large variations in temperature. It is found that vapor permeability influences both vapor and thermal transport while thermal conductivity influences only thermal transport. The vapor transfer coefficient has a small influence on vapor transport while the convective heat transfer coefficient has an influence on heat transport. The validated hygrothermal model is further used to simulate the coupled vapor and heat transport occurring in moisture buffering tests. It is found that moisture buffering values are different by up to 14% depending on the presence or absence of thermal insulation around the samples. For more hygroscopic materials, the difference can be even much larger. It is recommended not only to seal and but also to insulate samples for moisture buffering tests.

Short-Term Climatic Effect of Gyaring and Ngoring Lakes in the Yellow River Source Area, China

Based on the field observation and WRF-CLM model, the effects of Gyaring and Ngoring lakes on the short-term climate over the Yellow River source area during May to September have been studied through two experiments with and without the lakes. A backward water vapor transfer model was also employed to investigate the contribution of water vapor evapotranspiration from the Gyaring and Ngoring lakes and various surface types to the local precipitation. The results show that without the Gyaring and Ngoring lakes, the sensible heat is increased by 120%, whereas the latent heat is decreased by 58.5%, and the height of atmospheric boundary layer increases from 500 to 1,500–2,000 m during daytime over the lake area. The sum of sensible and latent heat fluxes in the lake area simulated by the experiment with and without the lakes is 185.8 and 130.3 W m−2, respectively. The precipitation amount over the lake area is significantly increased without considering the lake effect, generally by more than 20–40 mm. About 63.8% of the total precipitation in Gyaring and Ngoring lakes is contributed by the external water vapor sources. The evapotranspiration from the grassland is the secondary water vapor source for the precipitation in the Yellow River source area, and 25.2% of the total precipitation is contributed by this source. Around 4.2% of the total precipitation in the lake area is contributed by the evaporation from the Gyaring and Ngoring lakes.

Water and nutrients recovery from synthetic source-separated human urine using AGMD

Human urine is one of the largest nutrient contributors to the municipal wastewater’s nutrient load, which, if not properly managed, may cause severe eutrophication in natural waters. Reclaiming the nutrients from source-separated urine could potentially substitute 20–25% of commercial fertilizers and save up to 30% of the energy consumption for biological nutrient removal. The present study investigated the performances of urine separation and water recovery using air gap membrane distillation (AGMD), which recovers water via vapor conversion and transfer across the membrane and concentrates urine salts. The effects of operation conditions (e.g., the temperatures and flow rates of feed and coolant) on water permeate flux were examined. The results show that a high permeate flux (~14 L·m−2·h−1) and a low specific ammonia transfer (< 0.1 g·L−1) were achieved under optimal operations of the feed flow rate and the temperatures. Increasing feed flow or cold coolant flow or the thermal gradients can substantially increase permeate flux. Moreover, the Stefan diffusion model was used to compare and validate the experimental observations. The actual operational parameters and membrane properties (e.g., feed/coolant temperatures, air gap thickness, and membrane thickness) were employed in the model calculation without any fitting or unknown parameters. The modeling and experimental results matched well and highlights the promising potential of this model for guiding the design and operation of this AGDM process for urine separation and water recovery.

Different Pattern Designs with Printing Method on Classic Worsted Wool Fabrics

It is a well-known fact that the use of artificial fibers is increasing today. However, some reasons such as the high amount of chemicals, energy, water used in the production of artificial fibers and environmental pollution, allergic reactions on the skin it comes into contact with, and not being destroyed in nature for a long time have caused natural fibers have been preferred again. Among these fibers, which have been most preferred from the past to the present, wool fiber comes after cotton. The products produced from wool fiber provide the comfort features expected for the user in the best way, with their elasticity, drape, brightness, adaptability to the human body's thermal responses, and rapid transfer of heat and water vapor. Nowadays, the emergence of the need for functional and comfortable clothing in business life has necessitated different patterns and construction studies in wool fabrics. For this reason, different searches have emerged in conventional patterning (dobby patterning) techniques made on classical wool fabrics. The need to expand the boundaries of patterning studies created with conventional production techniques, different knitting, and yarn colors has led to the emergence of new patterns with printing techniques. In this study, different printing pattern studies were carried out on woolen dress/uniform fabrics in different constructions and weights. The pattern studies were carried out on woolen fabrics by using colors with different themes. As a result of printing patterns on woolen fabrics, it was aimed to increase the use of wool-based products in daily clothing.

Assessment on the effects of PEM and separator thickness under high temperature conditions by heat balance model considering vapor transfer

Assessment on the effects of PEM and separator thickness under high temperature conditions by heat balance model considering vapor transfer

Preparation and defect structure analysis of near-stoichiometric lithium tantalate wafers

A vapour transfer equilibrium (VTE) method has been used to prepare near-stoichiometric lithium tantalate (NSLT) crystals with different Li contents. The NSLT crystals were tested and analyzed by differential thermal analysis (DTA) and X-ray photoelectron spectroscopy (XPS) to investigate the effect of Li content on the Curie temperature and internal defects of NSLT crystals. This study found that when the Li content increased in the NSLT wafer, the binding energy corresponding to the peak of the Ta4f electron layer in the XPS spectrum first decreased and then increased, indicating that the proportion of Ta valence states was different in wafers with different Li contents. From XPS energy spectrum analysis, it can be seen that the lithium tantalate crystal contains Ta5+, Ta4+, Ta3+ and lower-valence Ta. As the Li content increases in the NSLT wafer, Ta4+ disappears and the proportion of Ta5+ decreases initially, follows by a later increase and then subsequent further decrease. However, the change in proportion of Ta3+ and lower-price Ta is completely opposite to that of Ta5+, showing a trend of first rising, then falling and then finally rising again. Moreover, when the Li content is 49.751% in the NSLT wafer, the proportion of Ta5+ reaches a maximum, showing that at this Li concentration the NSLT crystal has a more perfect lattice structure. In this study, we propose a mixed defect model in which polarons coexist with Li vacancies and Ta inversion, explaining the change in Ta valence state in lithium tantalate crystals. This model is more in line with the observed results in this work. The new hybrid defect model and the variation law of Ta valence state with Li concentration proposed in this paper provide a new direction and experimental proof for the defect study of NSLT crystals, and also provide a theoretical basis to explore the Li content at the best physical properties of NSLT crystals.

Impact of Separator Thickness on Temperature Distribution in Single Polymer Electrolyte Fuel Cell Based on 1D Heat Transfer

It is known from the New Energy and Industry Technology Development Organization (NEDO) roam map Japan, 2017 that the polymer electrolyte fuel cell (PEFC) power generation system is required to operate at 100°C for application of mobility usage from 2020 to 2025. This study aims to clarify the effect of separator thickness on the distribution of the temperature of reaction surface (Treact) at the initial temperature of cell (Tini) with flow rate, relative humidity (RH) of supply gases as well as RH of air surrounding cell of PEFC. The distribution of Treact is estimated by means of the heat transfer model considering the H2O vapor transfer proposed by the authors. The relationship between the standard deviation of Treact-Tini and total voltage obtained in the experiment is also investigated. We can know the effect of the flow rate of supply gas as well as RH of air surrounding cell of PEFC on the distribution of Treact-Tini is not significant. It is observed the wider distribution of Treact-Tini provides the reduction in power generation performance irrespective of separator thickness. In the case of separator thickness of 1.0 mm, the standard deviation of Treact-Tini has smaller distribution range and the total voltage shows a larger variation compared to the other cases.

An analytical study on sublimation process in the presence of convection effect with heat and mass transfer in porous medium

The mathematical study of one dimensional heat and mass transfer phenomena is investigated. A Stefan like phenomena is defined as a heat and mass transfer problem with presence of convection in vapour region for heat and moisture flow and convective term due to mass transfer of the water vapour in frozen region. The sublimation process considered in two region: (i) In frozen region, s(t)<x<∞, there is no effect of moisture in this region. (ii) In vapour region, 0<x<s(t), there is an effect of heat and moisture flows. The thermo-physical properties of each region are constant, but may be differ for different region. The analytical solutions are obtained for the temperature and moisture profile and moving sublimation interface by using the similarity transformation procedure. The effect of some parameters included in the sublimation process with various enclosures, i.e. dimensionless quantity l0, Peclet number Pe, Luikov number Lu, KT, a21 and other constant parameters are comprehensively investigated and represented graphically.

Синтез карбида и диборида титана для металлообработки и получения керамики

Introduction. Titanium carbide and diboride are characterized by high values of hardness, chemical inertness and for this reason are widely used in modern technology. This paper provides information on the synthesis of titanium carbide and diboride by carbothermal and carbide-boron methods, respectively, on the use of titanium carbide as an abrasive and in the manufacture of tungsten-free hard alloys, carbide steels, wear-resistant coatings, as well as titanium diboride in the production of cutting tools and ceramics based on boron carbide The aim of this work is to study the processes of synthesis of highly dispersed powders of titanium carbide and diboride, which are promising for the manufacture of cutting tools, wear-resistant coatings, abrasives and ceramics. Research methods. Titanium oxide TiO2, nanofibrous carbon (NFC), and highly dispersed boron carbide were used as reagents for the synthesis of titanium carbide and diboride. Experiments to obtain titanium carbide were carried out in a resistance furnace, and titanium diboride in an induction furnace. X-ray studies of the phase composition of titanium carbide and diboride samples were carried out on an ARL X-TRA diffractometer (Thermo Electron SA). The determination of the content of titanium and impurities in the samples of titanium carbide and diboride was carried out by the X-ray spectral fluorescence method on an ARL-Advant'x analyzer. The total carbon content in the titanium carbide samples was determined on an S-144 device from LECO. The content of boron and other elements for titanium diboride samples was determined by inductively coupled plasma atomic emission spectrometry (ICP AES) on an IRIS Advantage spectrometer (Thermo Jarrell Ash Corporation). The surface morphology and particle sizes of the samples were studied using a Carl Zeiss Sigma scanning electron microscope (Carl Zeiss). The determination of the particle/aggregate size distribution was performed on a MicroSizer 201 laser analyzer (BA Instruments). Results. The paper proposes technological processes for obtaining highly dispersed powders of titanium carbide and diboride. The optimum synthesis temperature for titanium carbide is 2,000…2,100 oC, and for titanium diboride 1,600…1,700 oC. The content of the basic substance is at the level of 97.5…98.0 wt. %. Discussion. A possible mechanism for the formation of titanium carbide and diboride is proposed, which consists in the transfer of vapors of titanium oxides to the surface of solid carbon (synthesis of titanium carbide) and vapors of boron and titanium oxides to the surface of solid carbon (synthesis of titanium diboride). Due to the high purity and dispersion values, the resulting titanium carbide powder can be used as an abrasive material and for the manufacture of tungsten-free hard alloys, carbide steels, wear-resistant coatings, and titanium diboride powder can be used for the preparation of cutting tools and ceramics based on boron carbide.

Analysis and characterization of additive manufacturing processes

Recently, additive manufacturing (AM) processes have expanded rapidly in various fields of the industry because they offer design freedom, involve layer-by-layer construction from a computerized 3D model (minimizing material consumption), and allow the manufacture of parts with complex geometry (thus offering the possibility of producing custom parts). Also, they provide the advantage of a short time to make the final parts, do not involve the need for auxiliary resources (cutting tools, lighting fixtures or coolants) and have a low impact on the environment. However, the aspects that make these technologies not yet widely used in industry are poor surface quality of parts, uncertainty about the mechanical properties of products and low productivity. Research on the physical phenomena associated with additive manufacturing processes is necessary for proper control of the phenomena of melting, solidification, vaporization and heat transfer. This paper addresses the relevant additive manufacturing processes and their applications and analyzes the advantages and disadvantages of AM processes compared to conventional production processes. For the aerospace industry, these technologies offer possibilities for manufacturing lighter structures to reduce weight, but improvements in precision must be sought to eliminate the need for finishing processes.