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The main research content of this project is the water recovery efficiency of the hot-pressure-driven air water-taking device when the phase-change material is used for energy supply, and combined with the research process, an automatic water-taking device using desert temperature difference and phase-change material storage is designed. At a time when energy sustainability is of great concern, we must make the development of green energy a core goal. Among them, solar energy as a green non-polluting new energy, its development and utilization is an important research topic and direction. The desert areas have plenty of solar energy and enough temperature differences to take advantage of these two resources and combine the lack of fresh water in the area. The purpose of this project is to design a device that uses phase-change materials to store heat to provide heat pressure, guide air directional flow, and use high-efficiency coaxial water collection sails for air water collection, with less human and material input, to obtain the fresh water necessary for life. And from the theoretical and physical level to demonstrate its feasibility, explore the direction of marketing.

This paper provides a justification for the assessment of the effectiveness of the use of air-water heat pumps in the heating systems of individual residential buildings in conjunction with the water boiler. The criterion for the cost-effectiveness of the heating system with a combined heat source is the relative cost of equipment and operation of the system, given to the duration of the heating period. Cost components are presented in the form of a system of equations reflecting the dependence of the price parameters of heating system equipment on thermal characteristics. The proposed method of assessing the benefits of renewable energy is applicable to different climatic areas.

With the gradual aggravation of desertification, aquatic plants are very rare, rain is scarce, and the air is very dry in desert areas, which poses unprecedented challenges to the survival of local residents. In order to solve the crisis of lack of fresh water, the research on air water intake was carried out, and the corresponding design of air purification device was carried out. The benefit and feasibility of the air purification device were analyzed by using the model and software.

The auxiliary navigation device described in this paper can effectively make up for the shortcomings of the existing navigation mode. It has designed a targeted detection module for various unstable factors in complex waters, such as large ship flow, frequent water level changes, low visibility, hidden reefs and floating ice. With the advantages of both water and air, excellent navigation performance and all-round detection means on water and underwater, the device can achieve excellent auxiliary pilot effect. In addition, the device has the advantages of low operation difficulty, short training period, high safety, good social and economic benefits, which is suitable for wide range promotion in navigation areas such as ports, inland rivers and coastal areas.

The work is devoted to the spread processes mathematical modelling of impurities in a reservoir in areas located far from river runoff. An aerodynamic processes mathematical model is proposed that takes into account a variety factors: increased air humidity, variability of atmospheric pressure and temperature, etc. The model discretization was carried out taking into account the partial filling of the calculated cells, which made it possible to significantly reduce the error at the boundary. For the calibration and verification of the pollutants transport model, the expeditionary research data were used.

This paper designs an air intake device based on Peltier effect to solve the problems of insufficient per capita water use and difficult survival of living organisms in water-scarce areas in China. It uses semiconductor to refrigerate, takes water from the air in a cooling condensation way, uses wind power and solar energy to supply power for the refrigerator continuously. Through data analysis, the device can effectively collect air moisture and condense to produce liquid water, which has broad application prospects in arid areas in northwest China.

The article deals with theoretical and experimental studies of oily industrial wastewater flotation treatment using a saturator and vortex mixing devices (VMD) for preparing a water-air mixture. The use of VMD allows, in comparison with the saturator, to improve the efficiency of oil product removal on the flotator by 5-7% due to the greater gas saturation of the flotation volume. The energy consumption for preparing the water-air mixture in vortex mixers was on 8–10% lower than in flotation plants using a saturator.

The present study focused on evaluating the heat transfer behavior and predicting the surface resulting status during air/water droplets two-phase flow. Transient heat transfer based on the lumped capacitance model (LCM) was investigated experimentally under a range of water droplets concentration, surface temperature, and varying Re number. Compared with a single-phase air cooling, the transient surface temperature decreased with the increase in water droplets concentration and Re number. At the same cooling time, the surface temperature decreases about 13.5%, 47%, and 53.2% for (j = 46.79 – 111.68 kg/m2 hr). It was also noticed that the heat transfer coefficient increased with the increase in water droplets concentration and reach its maximum value at (j = 111.68 kg/m2 hr). Based on the analysis of the experimental results, the heat transfer mechanism due to the impacting of water droplets on the sphere surface was classified into three important physical regimes. Clear convection heat transfer regime corresponds to the dry region (region I); Convection and evaporation regimes correspond to the dry-out and wet regions (region II and III).

Unmanned Aerial-Underwater Vehicles have been envisioned as a new kind of hybrid unmanned system capable of performing equally well in multiple mediums and seamlessly transitioning between them. Currently, bio inspired vehicles are leading the way in the development of such a vehicle, that can fly like an eagle and swim like a fish. This path-breaking amphibious aerial underwater vehicle is sought after because of its wide range of applications in military, commercial and civil environments. From aerial surveillance, deep water exploration to underwater non-destructive testing, this vehicle aims to do it all. However, the development of a fully functional version is hindered by the significantly different properties of air and water, considering the air water transition, different propulsion systems and stability underwater. We evaluate these available architectures that aim to accomplish the goal of creating a flawless multi-medium unmanned vehicle which has its limitations as one of the modes is dominant leaving the other to be at a lesser than expected measure. This paper presents a survey discussing the evolution of these systems by first looking at their parent systems and then evaluating the various existing types of UAUVs by understanding their working mechanisms. The paper aims to provide a comprehensive overview of the work done in the field so far which can provide direction to the further development of such vehicles.

This paper presents the results obtained from the modeling of the flow and heat transfer in the condenser of the heat pump used for heating the water of a pool, by means of CFD analysis. Using the k-∈ turbulence model its real behavior was described; these data may be useful to propose the improvement of its thermal design. The distributions of temperature, pressure, and velocity, both for the water and the R-410A refrigerant were obtained. The value of the COP of the pump which was 7.6 was found through the results. The experimental value of this variable was 7.32, both values are lower than those offered by the manufacturer of this equipment.

An experimental investigation on a horizontal two-phase air-water jet has been conducted in order to develop a technique that can provide information on the interaction between the air bubbles and turbulent flow. In order to allow a measurement of the liquid phase flow field and of the bubbles size, the Particle Image Velocimetry (PIV) has been used, with the liquid phase seeded with a fluorescent tracer consisting of Rhodamine WT mixed with a commercial polyester resin. A phase discrimination algorithm has been developed and successfully used for the detection and separation of tracers and bubbles in distinct images. Three data sets have been recorded: one for a one-phase water jet and two for a two-phase water jet. The obtained results allow a valid characterization of the flow field and an estimation of the effect of the gaseous phase in the air-water jet flow. An analysis of the bubbles size and number has been also conducted and here reported.

In this paper, the experimental and theoretical analysis of pressure drop in single-phase and two phase-flow were presented for straight and U-bend smooth tube annulus and tube annulus with wire coil insert. Experiments for various boundary conditions were performed. In case of U-tube and straight tube with and without turbulator, tests were made for the water-water and air-water systems. The study covered a wide measuring range, i.e. Vw = 9*10-5-8.87*10-6 m3/s - for water, and Va = 5.55*10-5 m3/s.-for air. The test elements were made from a copper pipe with an external diameter of 10 mm and 18 mm and wall thickness 1 mm. The helicoidal vortex generator was made from brass wire with a diameter of 2.4 mm, coil diameter 13 mm and pitch 11 mm. For these geometries, the values of pressure drop and heat flux were determined. Obtained experimental results were compared with correlations from literature. The best coherence with database were obtain for Lockhart-Martinelli and Sugawar et al. models for two-phase flow regime.

The WC/a-C film prepared using a reactive magnetron sputtering system was investigated. The film structure and properties were characterized, and the friction response mechanism between this film and several counterparts was investigated under different environments. The hardness and surface roughness of the counterpart as well as the match between the properties of the counterpart and the film were identified as factors that play a critical role in the friction behaviour. The environment affected the extent of wear through physical and chemical reactions, and mechanical wear with friction chemical reactions was found to be the major mechanism of influence. This study is of great practical interest, as it will help to extend the service life of WC/a-C films and minimize loss during the initial running-in period.

In this work, a density functional approach is applied to calculate the interfacial thermodynamic properties of an air-water mixture in the presence of a hydrophobic wall. Without any mixing parameter, the theoretical model can correctly reproduce the measured interfacial tensions of a nitrogen-water binary mixture. The density profiles of the dissolved air and water near the hydrophobic walls are predicted using the validated model. It is shown clearly that a hydrophobic wall leads to air enrichment and water depletion. According to the extent of air enrichment, the free energy barriers and critical radii of bubble nucleation at different hydrophobic interfaces are calculated to evaluate the possibility of spontaneous bubble nucleation.

A theory is presented which describes the interaction between a cylindrical element and a bubble front and rear interface, and these results are used to interpret the heat transfer effects from a hot-film probe in contact with a bubble. Stepwise interface tests were carried out to test the main features of the developed theory, and a good agreement was demonstrated. However, bubbly two-phase flows are dynamic situations, and dynamic interface and single-bubble tests were also carried out to evaluate the additional dynamic effects. These results emphasised the main features of the static theory and tests, and confirmed that dynamic effects related to distortion of the menisci, meniscus formation and film stability must be included to describe correctly the response of a hot-film probe to the passage of a bubble. Tests were carried out for both air/water and kerosene/water mixtures and in both cases similar responses were obtained.

The design, manufacture and calibration of a range of thin-film, heated-element gauges to measure instantaneous velocity or skin-friction in air, water or blood is described. The probes consist of a platinum resistance thermometer which is heated electrically, with additional elements to detect reversed flow. The manufacturing technique of a flush-mounted skin-friction gauge, and a needle probe currently used in the diagnosis of heart conditions in man, is described in detail.

Effect of Film Thickness on Instability in Bubble Velocity of Magnetic Garnet Films Hideo Nakanishi and Chikao Uemura Measurement of two-dimensional bubble velocity by Using tri-fiber-optical Probe Ruichang Yang, Rongchuan Zheng, Fanling Zhou et al. Effects of viscosity on the growth of RT instability Y G Cao, H Z Guo, Z F Zhang et al. Experimental verification of the four-sensor probe model for flow diagnosis in air water flow in vertical pipe S Pradhan and R Mishra High-quality electron beams generation in a linear upramp density target Q. Yu, Q. Kong, Y. J. Gu et al. Some remarks on the response of hot-wire and hot-film probes to passage through an air-water interface K Remke Temperature Dependence of Instability in Bubble Velocity in Garnet Films