Tank Model Research Articles

Modeling district heating pipelines using a hybrid dynamic thermal network approach

A novel numerical method is presented for fast and accurate simulation of the dynamic thermal behavior of buried pipelines such as those in district heating systems. The model is based on a combination of a conduction response factor method, known as the dynamic thermal network (DTN) method and a one-dimensional discretized heat transfer fluid flow model, the so-called plug flow N-continuously stirred tanks (PFST) model. This combination enables the model to effectively take into account the short timescale dynamic effects of pipelines including longitudinal dispersion of turbulent fluid and its thermal capacity and also transient ground heat transfer. The combined DTN-PFST model is validated by reference to experimental data from both the lab-scale representation of a district heating system and monitoring data from a full-scale operational system. The comparisons between simulation results and experimental data demonstrate a good level of accuracy of the proposed model in predicting the dynamic thermal behavior of pipelines. The model has also been found to be several orders of magnitude more computationally efficient than corresponding 3D numerical models. Both the accuracy and computational efficiency of the proposed model make it well-suited to the design and analysis of district heating distribution networks. The model is also expected to be well-suited to the modeling of horizontal ground heat exchange pipe systems.

EXPERIMENTAL STUDIES OF PRESSURE CHANGES IN THE GAS SPACE OF OIL STORAGE TANKS

Vertical steel tanks are a significant part of the main oil pipelines in terms of cost, purpose, and environmental impact. More than 30 % of vertical steel tanks will never be equipped with pontoons and floating roofs, but will be equipped with breathing valves, which are an ineffective means of reducing losses. The creation of excess pressure in the gas space of the tank requires control over it, while for tanks that have been in operation for a long time, a decrease in excess pressure and vacuum is allowed due to leakage of individual tank components. During the study, experiments were carried out to determine the change in pressure on 6 model tanks with a changing and stable filling level. As a result, it was revealed that it is necessary to analyze the change in pressure in the gas space of the reservoir by the operating organization online. This will allow timely detection of deviations in the operation of the tank and take the necessary action.

Numerical and experimental study of stern flaps impact on resistance and propulsion of high–speed displacement ships

This study investigates hydrodynamic interactions between a high-speed displacement ship and various stern flap configurations. It combines towing tank model tests and advanced Computational Fluid Dynamics (CFD) simulations to explore hydrodynamics and energy-saving potential. Sixteen flap combinations were tested across Froude numbers (Fn) from 0.198 to 0.452 to understand post-installation hydrodynamics and energy-saving potential. The alignment between model tests and CFD simulations reinforces the potential of stern flaps to enhance efficiency and environmental friendliness in high-speed displacement vessels with transom sterns. CFD enhanced visualisation of flow, pressure, and other hydrodynamic parameters. The study reveals that the stern flaps reduce resistance and effective power, saving energy across all the combinations. However, the effectiveness of the flaps is limited at lower speeds (Fn < 0.198), where increasing flap angles incur higher resistance penalties. The greatest decrease in resistance is noted when the Froude number (Fn) is at 0.367, with a subsequent reduction after that. Stern flaps influence trim, sinkage, and hydrodynamic length, reducing wave-making resistance without increasing friction. Increased wake fraction and reduced thrust deduction enhance propulsion efficiency, while stern flaps suppress waves, lowering overall resistance. A reduction of effective power by 6% was observed in the present study. This research provides valuable insights into stern flap hydrodynamics and energy-saving potential, guiding ship design and operation.

COMPARATIVE ANALYSIS OF COMBAT CAPABILITIES OF MODERN TANKS OF VARIOUS TYPES

Modern war is a test of the material and spiritual forces of the people, the state and its Armed Forces, which prompts each country to maintain its defense capability at a level that guarantees reliable protection of society. Analysis of the nature of armed conflict in recent decades shows a sharp increase in the impact of modern weapons and military equipment on the course and outcome of military operations. Currently, weapons and military equipment form the basis of the combat power of the armed forces of any state and are the determining factor in achieving success in war or armed conflict. Despite the rapid development of anti-tank weapons and the decrease in survivability on the battlefield, main battle tanks remain one of the decisive means of modern combined arms combat, which is characterized by dynamism, saturation and speed. They provide the combat stability of their own forces in defense and advance during the offensive, destroy enemy armored vehicles, fire points and living forces. A comparative analysis of the main characteristics of modern combat tanks, the advantages and disadvantages of various types of vehicles of foreign and domestic production, used by the Armed Forces of Ukraine for the defense of the state and countering the aggression of Russia against Ukraine, in order to improve the effectiveness of their use in different conditions of combat. Western models of modern tanks and the Ukrainian tank "Oplot" in some significant combat characteristics prevail over the modern Russian tank T-90, in particular: in the power of the engine and its reliability of operation (engine overheating and failure); in the effectiveness of optoelectronic counteraction to optical enemy means; in the effectiveness of dynamic protection and countering modern weapons; in the perfection of the fire control system; in the sufficiency of the armor of the machine; in the effectiveness of actions in urban conditions. Keywords: war, battle tank, tactical and technical characteristics, effectiveness, comparative analysis

Reduced-scale numerical simulation method and its application to urban-scale buoyancy-driven flows

Urban-scale flows such as urban heat island circulation dominate the dissipation of heat and pollutants in urban areas under calm and stable weather conditions. The study of such buoyancy-driven flows at an urban scale is commonly conducted using water tank modeling and numerical simulations. This paper adopts an approach called "numerical water tank" which utilizes computational fluid dynamics to simulate the water tank model. By adopting this method, the research aims to investigate and analyze urban-scale buoyancy-driven flows. This paper proposes an evaluation criterion to assess eight turbulence models in various aspects. The results show that the SST k-ω model and LES perform well. LES is more accurate than RANS, and compared with LES, SST k-ω model can save 1/3-1/2 of the calculation time. For two-equation turbulence models (k-ε and k-ω), which are known for their easier convergence, it is recommended to maintain a Courant number equal to or below 1 (time step 0.5 s). In the case of LES, which is known for its challenging convergence, it is recommended to maintain a control Courant number below 0.2 (time step 0.1s). On this basis, the numerical water tank method based on large eddy simulation is applied to quantitatively study the effect of canopy heat flux attenuation on urban-scale wind field characteristics in valley cities. This paper combines the strengths of water tank modeling and numerical simulation, resulting in a more efficient approach for studying large-scale flows driven by natural thermal pressure.

A finite element analysis-based approach for blast-resistant design of LNG containment tanks

Inside Liquid Natural Gas (LNG) facilities, ignition of large vapor clouds in a congested region might result in Vapor Cloud Explosions (VCE) leading to high speed blast waves and compromising the structural integrity of equipment and structures. The escalation of an initial blast is referred to as ‘Cascading Effect’. In performing risk assessment of a facility, structural damage of LNG containment tanks due to blast scenarios needs to be considered. This article presents a numerical approach-based methodology to analyze containment structures using Finite Element Analysis (FEA). The objective of this study is to elucidate the critical parameters in blast resistant design of containment tanks. Four major types of containment tanks are studied under representative scenarios of deflagration and detonation. Containment tank geometries were created almost in its entirety and the structural response is modeled with appropriate constitutive relations for steel and concrete. Additionally, pertinent hard contact with friction interaction between the tank inner to outer shell surfaces are assigned. The results indicate that a single containment tank model experienced severe damage in its outer shell under deflagration compared to other types of containment tanks. In the case of double, full and membrane containment tanks cracking in the prestressed concrete wall was observed due tensile damage which is pronounced for detonation than for deflagration cases. It is concluded that single containment tanks are most vulnerable to Cascading Effect. Based on the results of FEA, recommendations are provided for safe practice of designing the structures and maintaining the structural integrity of tanks.

Coupled dynamics of the moving Antarctic krill trawl structure and its hydrodynamics behavior using various catch sizes and door spreads based on wavelet-based and Fourier analysis

Antarctic krill is a key element of the complex ecology of the Antarctic Ocean and a target species for commercial fisheries for aquaculture supply, krill oil production, and as a major food source for various natural predators. Therefore, understanding the interaction between the fluid structures of the Antarctic krill trawl structure is the key factor in solving problems such as selectivity, energy efficiency, catchability, and ecological sustainability in this fishery. Thus, this study experimentally investigated the influence of catch sizes, door spread, and inflow velocities on the bridle tension, trawl motions, trawl deformation, and flow field inside and around a scaled trawl model in flume tank based on the electromagnetic current velocity meter measurements. Fourier analysis using power spectrum density and the continuous wavelet transform is used to analyze the time-frequency contents of the instantaneous flow velocities, bridle tension, and trawl motions; and in the interaction between the unstable turbulent flows and the fluttering trawl motions, wavelet coherency analysis was employed to detect coherent structures. Results indicated that the bridle tension and trawl motions increased as the catch size, door spread, and inflow velocity increased. Owing to the significant trawl deformation, a complex fluid–structure interaction occurred and a strong positive correlation between the bridle tension and trawl motions was obtained. Furthermore, a significant decrease in the flow field occurred inside and outside different parts of the trawl. Fourier and wavelet analysis results showed that the trawl motions and bridle tension are mainly of a low-frequency activity and of another component related to the unsteady turbulent flow street, and decreased with the increasing catch size and door spread. A complex fluid–structure interaction is then demonstrated where the hydrodynamics of the moving Antarctic krill trawl structure are an intricate interplay between trawl fluttering motions and unsteady turbulent flow influenced by catch size and door spread. The knowledge of such trawl hydrodynamic behavior is of great importance to understand and design the optimal structure of trawl nets to maintain the sustainability of the Antarctic krill fishery.

A novel approach for failure and consequence assessment considering multi-hazard coupling scenario in chemical industrial parks

As a typical high-risk area, nature hazards acting on chemical industrial parks (CIPs) can result in catastrophic multi-hazard coupling scenarios (MHCSs). Existing research mainly adopts a linear superposition method based on simplified assumptions to analyze the coupling amplified effects of multi-hazard. Therefore, the complicated nonlinearity of consequence superposition has not been intensively studied. In this study, a new dynamic graph-based methodology is established to investigate the nonlinear superposition mechanism, by addressing the failure consequence assessment of multi-hazard. A typical MHCS of the earthquake-fire sequence is adopted to demonstrate the proposed methodology, and the failure prediction model of earthquake-damaged tanks subjected to the earthquake-fire sequence is numerically developed to calculate the failure consequence more accurately. The results indicate that the seismic damage significantly reduces the fire resistance of steel cylinder tanks. Compared to intact tanks, the time to failure of seismic damaged tanks is reduced by up to 8.48 min at most, exacerbating the escalation of domino effects. The consequence modeling without the consideration of fire resistance attenuation may be severely underestimated by a factor of 1.35 to 2.13. This method can be used to predict the dynamic consequence of the typical MHCSs and mitigate such accidents via more flexible adjustment of emergency decision-making at each evolution stage.

Rainfall–runoff process and sediment yield in response to different types of terraces and their characteristics: A case study of runoff plots in Zhangjiachong watershed, China

AbstractA field experiment was conducted in the Zhangjiachong watershed to analyze the characteristics of rainfall–runoff process and sediment yield under different types of terraces. Various runoff plots were utilized, and a two serial tank model was employed to simulate runoff generation and concentration processes, taking into account vegetation interception. A soil erosion model incorporating raindrop erosion and sheet erosion was established to replicate sediment yield and concentration process. The parameters of the rainfall–runoff model and soil erosion model were calibrated and validated using observed runoff and sediment yield data. The controlling factors on runoff and sediment yield were explored and compared. The results indicate that both calibration and validation outcomes were acceptable. The earth‐banked terraces–citrus demonstrated the largest coefficients of upper and lower surface runoff, while its upper runoff threshold of the upper tank and the runoff threshold of the lower tank were the lowest, suggesting that it was more likely to produce surface and subsurface runoff. On the other hand, the stone dike terraces–crops exhibited the smallest coefficients of upper and lower surface runoff, while its upper runoff threshold of the upper tank was the highest. The lower runoff threshold of the upper tank was the same across different types of terraces. Compared to the earth‐banked terraces, the stone dike terraces have a larger infiltration coefficient in the upper tank and a smaller infiltration coefficient in the lower tank. Sensitivity analysis indicates that the most sensitive factors affecting runoff simulation results are the runoff threshold and the infiltration coefficient of the lower tank. Terraces, whether constructed with earth banks or stone dikes, are effective in reducing soil erosion. However, during storm rainfall events, these terraces may be partially destroyed, resulting in a higher sediment yield than that of the same vegetation cover on slope land. Terraces with hedgerows have a more significant effect on reducing runoff and sediment than those without hedgerows.

Autonomous GPU-based UAS for inspection of confined spaces: Application to marine vessel classification

Inspection of confined spaces poses a series of health risks to human surveyors, and therefore a need for robotic solutions arises. In this paper, we design and demonstrate a real-time system for collecting 3D structural and visual data from a series of inspection points within a prior map of a confined space. The system consists of a GPU accelerated 3D point cloud registration and a visual inertial odometry estimate fused in an Unscented Kalman Filter. Using the state-of-the-art deep learning-based feature descriptors, FCGF –and the robust Teaser++ 3D registration algorithm– point clouds from a narrow field of view, time-of-flight, camera can be registered to a prior map of the environment, to provide accurate cm-level absolute pose estimates. The uncertainty of the system is furthermore estimated on the basis of the novel GPU-based Stein ICP algorithm. Visual defects, represented by augmented reality fiducial markers, are automatically detected during inspection, and their positions are estimated in the map frame of the confined space. The performance of the system has been evaluated in realtime onboard a small UAV, within a mock-up model of a water ballast tank from a marine vessel, where the UAV was able to navigate and inspect the ambiguous and featureless environment. All defects were estimated within ＋/−10 cm of their actual position.

INCREASING THE ENVIRONMENTAL SAFETY LEVEL OF THE TERRITORY ADJACENT TO LOCATIONS OF LIQUID HYDROCARBON RESERVOIRS

Accumulation of flammable and combustible liquids on a relatively small area of the tank park leads to an increased environmental and fire hazard of such productions. The possible leakage of dangerous liquid and depressurization of tanks negatively affects the state of the environment in the surrounding area. A fire in a tank is one of the most dangerous emergency situations that could lead not only to significant material and environmental damage, but also to human casualties. The situation is also complicated by the economically determined tendency to use larger tanks, which significantly increases the volume of flammable liquids per unit area. This, in turn, increases the risk of fire spreading to neighboring tanks in the absence of timely localization and elimination of the fire. It is urgent and necessary to improve the methods of researching the properties of the materials of liquid hydrocarbon tanks and to assess the effects of external factors of natural and technogenic origin on these environmentally dangerous objects. The method of determining the dynamic characteristics of shell structures made of steel and partially filled with liquid (petroleum products) has been developed in the paper. A numerical analysis of the dynamic characteristics for the model of tanks for the storage of liquid hydrocarbons has been carried out. The optimal parameters of shell structures to reduce their deformations during fluid oscillations (using the example of liquid hydrocarbons) have been determined. It has been proved that taking into account the elasticity of the tank walls leads to a significant decrease in the oscillation frequencies compared to the frequencies of unfilled shells, while the lowest frequencies of filled and unfilled shell structures can correspond to different wave numbers. Extending the service life of tanks, preserving their tightness and stability under various natural and technogenic influences, preventing leaks, spills and fire hazards is necessary to increase the level of environmental safety of the surrounding territories.

Simplified earthquake response analysis of rectangular liquid storage tanks considering fluid-structure interactions

A simplified model of a rectangular liquid storage tank is proposed to estimate the earthquake responses of the system while considering the effects of fluid-structure interactions. The complicated three-dimensional structural behavior of a rectangular tank is represented by the simple combination of the fundamental modes of a rectangular-ring-shaped frame structure and a cantilever beam. The governing equation for the system is derived from Lagrange’s equation. The earthquake responses of deflection, hydrodynamic pressure and its resultant force and moment, base shear and overturning moment due to the structural deformation are obtained from the solution of the governing equation. The effective masses of the system and their heights are presented with the effective added masses and their heights from the hydrodynamic effects. The total earthquake responses are obtained with the convective earthquake responses taken into consideration. The proposed simplified model is applied to example rectangular liquid storage tanks with various aspect ratios, and the accuracy of the model is demonstrated. The proposed simplified model can be employed for the seismic design of a rectangular liquid storage tank, and reliable estimations for earthquake responses of the considered fluid-structure interaction system are obtained without sophisticated and/or complicated dynamic analysis.

Experimental study on the wind-induced buckling of open-top storage tanks with wind girders via 3D-DIC technique

Large open-top storage tanks are susceptible to buckling failure under the combination of external and internal wind pressures. Therefore, wind girders are recommended to be installed on the tank wall to improve its buckling capacity. Most previous experiments on buckling of cylindrical shells typically measured the response at a certain point with a single displacement sensor, and the buckling modes are not readily available. In this study, a measurement technique based on the three-dimensional digital image correlation method is utilized to analyze the buckling behavior of several elastic tank models with aspect ratios of 0.5 and 0.2 in the boundary layer turbulence. The critical buckling pressure and instantaneous displacement field on the windward side of models with and without wind girders are presented and compared with the results of finite element analysis. In addition, the effects of wind girders and imperfections are further discussed. The results indicate that the deformation of the tank wall can change the wind pressure, making it more difficult to return to the pre-buckling state. The wind girders can significantly restrain the buckling deformation and increase the critical buckling load. However, as the wind girders become rigid, the strengthening effect becomes almost constant, and the stiffened tanks are more sensitive to initial geometric imperfections. Based on the cylindrical shell buckling theory and existing calculation methods, an empirical formula for the critical buckling wind pressure of open-top storage tanks with different numbers of wind girders in the boundary layer is proposed.

Underwater Radiated Noise Prediction Method of Cabin Structures under Hybrid Excitation

Aiming at the engineering limitations of traditional ship vibration online monitoring and noise prediction methods, this paper proposes a method for online monitoring and underwater radiation noise prediction of cabin structures’ vibration and noise under hybrid excitation of sound and force. The method first constructs the condition test model; based on OTPA technology, the “acoustic-vibration” transfer function between sound and vibration monitoring points in the cabin and the “acoustic/vibration-acoustic” transmission network inside and outside the cabin structure are obtained. Secondly, based on the “acoustic-vibration” transfer function, the online vibration and sound monitoring data are decoupled and processed to obtain the modified vibration and sound monitoring data. Finally, the near-field radiation noise on the conformal hologram surface outside the cabin is predicted based on the “acoustic/vibration-acoustic” transmission network, and the far-field radiation noise of the cabin structure is predicted by the wave superposition method. In this paper, the contribution law of external radiation noise and the coupling characteristics of the monitoring information under the hybrid excitation of sound and force are analyzed theoretically, and the decoupling method of coupling information is also studied. This method makes up for the problem of missing underwater radiation noise caused by sound excitation in traditional vibration monitoring, and it can effectively improve the prediction accuracy of underwater radiation noise. The effectiveness of the method is further verified by the tank model experiments.

Numerical simulation and optimization analysis of low temperature adsorption hydrogen storage

In this paper, a two-dimensional axisymmetric hydrogen storage tank model is established based on the D-A model using software to simulate the activated carbon adsorption hydrogen storage filling process numerically. The distribution of pressure inside the tank under the boundary conditions of 0.5 atm–1 atm is obtained, and the trends and rates of pressure changes inside the tank under different boundary conditions are compared. The temperature distribution inside the tank is investigated under the initial temperature of 293.15 K, the external condition of 77 K, and the convective heat transfer coefficient inside and outside the tank is 20 W/(m2·K), and the influence of adsorption materials on the temperature distribution inside the tank is compared with that of different thermal conductivity coefficients, and the general trend is that the temperature is higher and then lower, the temperature inside the tank is relatively high near the center axis, and the temperature near the tank wall is relatively low, and the addition of ribs can The addition of ribs can reduce the temperature inside the tank. This paper also calculates the adsorption amount of hydrogen at different pressures (0–7 MPa) and temperatures (80 K–260 K), and finds that the adsorption amount is the largest at 80 K and 7 MPa, with a value of 39.3 mol/kg. The novelty of this study is the coupling of many different physical fields to bring the results closer to reality and to give directions for optimization.

The Static and Dynamic Behavior of Steel Storage Tanks over Different Types of Clay Soil

Steel storage tanks are widely used in different fields. Most of these tanks contain hazardous materials, which may lead to disasters and environmental damage for any design errors. There are many reasons which cause the failure of these tanks such as excessive base plate settlement, shear failure of soil, liquid sloshing, and buckling of the tank shell. In this study, five models of above-ground steel storage tanks resting over different types of clay soils (medium-stiff clay, stiff clay, and very stiff clay soils) are analyzed using the finite element program ADINA under the effect of static and dynamic loading. The soil underneath the tank is truly simulated using a 3D solid (porous media) element and the used material model is the Cam-clay soil model. The fluid in the tank is modeled depending on the Navier–Stokes fluid equation. Moreover, the earthquake record used in this analysis is the horizontal component of the Loma Prieta Earthquake. The analyzed tanks are circular steel tanks with the same height (10 m) and different diameters (ranging from 15 m to 40 m). The soil under the tanks has a noticeable effect on the dynamic behavior of the studied tanks. The tanks resting over the medium-stiff clay (the weakest soil) give a lower permanent settlement after the earthquake because of its low elastic modulus which leads to the absorption of the earthquake waves in comparison to the other types of soil. There are 29.6% and 35.6% increases in the peak dynamic stresses under the tanks in the cases of stiff clay and very stiff clay soils, respectively. The maximum values of the dynamic vertical stresses occur at a time around 13.02 s, which is close to the peak ground acceleration of the earthquake.

Study on the Control of Saltwater Intrusion Using Subsurface Dams

Subsurface dams are widely used to prevent saltwater intrusion, with good results. This blockage often leads to an accumulation of pollutants and salt on the inland and seaside of the dam, respectively. While the latter is intended, the former effect is not desired and poses a huge problem in groundwater management. In order to quantitatively address this issue and clarify the impact of subsurface dam height, location, and the head difference for the saltwater and freshwater boundary on saltwater wedges and fresh groundwater discharge, a flow tank and numerical model were constructed. The results indicate that there was an optimal effective dam height and location (also the minimum effective dam location) for controlling saltwater intrusion, which corresponded to the maximum groundwater and freshwater discharge. When the various conditions of the numerical model were set according to the flow tank and the dam was 15 cm away from the saltwater boundary, the minimum effective dam height was equal to the aquifer thickness multiplied by 0.36. The dam height reached a height that was slightly higher than the minimum effective height, namely, the ratio of dam height to aquifer thickness was 0.38, which revealed that the freshwater discharge reached its maximum at 22.71 cm3/min, the saline water wedge area was the smallest at 378 cm2, and the prevention effect of saltwater intrusion was the best. Building a dam too high, that was, the ratio of dam height to aquifer thickness exceeded 0.38, resulted in an increased saltwater wedge area and exacerbated aquifer pollution. When the dam was located at the minimum effective distance for preventing saltwater intrusion under a certain dam height and head difference between saltwater and freshwater boundary, that was, the ratio of the distance of the dam to the saltwater boundary to the total length of the aquifer was 0.063, the distance of the dam to the saltwater boundary was the minimum effective distance. Compared to other effective distances, when the dam was at the minimum effective distance, the freshwater discharge reached its maximum at 22.71 cm3/min, and the saltwater wedge area was the smallest at 378 cm2. These conclusions provide a theoretical reference for the impact of subsurface dam construction on the saltwater wedge. This study examines the impact of tides and waves on the water head of the saltwater boundary, and it is also necessary to verify these conclusions through actual field experiments. We will investigate this in future work.

Numerical Research on Thermodynamic Properties of a Thermocline in Thermal Energy Storage Tank Based on Modified One-Dimensional Dimensionless Model

The application of thermal energy storage (TES) has been proved effective to improve the energy utilization efficiency of renewable energy and industrial waste heat energy. In this paper, a modified one-dimensional dimensionless model for the thermocline thermal energy storage tank is derived to simulate the system more accurately. An adaptive strategy for solving region compartmentalization is proposed for reducing computing time. Based on the proposed model, the effects of three different parameters on the performance of the thermocline tank are studied. The results show that increasing the inlet velocity can reduce the thickness of the thermocline and improve the system efficiency. Increasing the temperature difference between hot and cold water leads to a thicker thermocline, but the thermal energy stored in the tank increases. Increasing the tank height has no effect on the motion characteristic of thermocline, but the system efficiency can be increased.

Performance Evaluation of Rainfall-Runoff Models for Predictions of Inflows to Bhumibol Reservoir in Thailand

The Bhumibol reservoir in the Ping River basin is the largest reservoir in the Kingdom of Thailand. This reservoir has contributed to economic development of the country by supplying increased electricity and irrigation water demands as well as flood mitigation in riparian areas along the Ping and the Chao Phraya River. The prediction of inflows to the reservoir is crucial for the optimal management of water for irrigation, power generation and flood control. Properly customized rainfall-runoff models of the catchment could provide the basis for predicting the inflows to the reservoir. Hence, five lumped conceptual rainfall-runoff models were developed for the Ping River basin to simulate daily inflows to the Bhumibol reservoir. The rainfall-runoff models are Australian Water Balance Model (AWBM), Sacramento Soil Moisture Accounting Model, Simplified Hydrolog Model (SIMHYD), Soil Moisture Accounting and Routing Model (SMAR) and Tank Model. The evaluation of the performances of these models showed that all models are capable of predicting inflows. However, the SIMHYD, Sacramento, AWBM and Tank models perform better than SMAR model. Hence, these models could be employed for prediction of inflows to the reservoir with acceptable accuracy.

Investigate Air Well Turbines Performance for Power Generation by Tidal Waves in River

The phenomenon of climate change resulting from the increase of global warming has become one of the main problems facing the world. Where researchers and specialists have worked for many years to find a solution that reduces this phenomenon and limits its risks. It is likely that clean energy is an alternative to fossil fuel sources, which are the main source of global warming. One of the clean energy sources is ocean wave energy, which is a huge and untapped energy source, despite the possibility of extracting large energy from waves. This paper focuses on the study of deep-sea turbines and their results. A study was conducted on the capture chamber. Where this paper presents an experimental model of a water tank with certain dimensions in the university laboratories to describe the dynamic behavior of the capture chamber. The Froude number scale was used to model the dimensions and depth of the water as well as the wave properties. Through experimental work and its results show, and it was found that the power generated by the motion of the wave strength is related to the height and frequency of the wave.