A Comprehensive Study of Mass Accretion and Atmospheric Effect of Raindrop

The mass accretion of a raindrop in different layers of the atmosphere is not dealt with so far. A comprehensive brief study of the motion of raindrops through the atmosphere (i) without mass accretion, (ii) with mass accretion and (iii) finally pressure variation in the atmosphere with altitude using Bernoulli’s equation is illustrated. Acquirement of mass from moist air is mass accretion and mass accretion during the motion of raindrop through resistive medium holds an arbitrary power-law equation. Bernoulli’s equation when applied to it, the generalized first-order differential equation is reduced to a polynomial equation. Results show a single intersecting point of approximate terminal velocity 1 m/s and mass 10-06 mg as illustrated. Terminal velocity is achieved within 25 sec. There is the approximate exponential growth of terminal velocity. An increase in momentum is due to mass accretion during motion. Various conditions of no mass accretion and mass accretion show the same result while for atmospheric effect using Bernoulli’s equation the first-order differential equation reduces to a polynomial equation.

Theoretical and experimental study of motion and sinking time of Saxon Bowls

This work focuses on investigating the time of sinking of a Saxon bowl proposed by ‘International Young Physicists’ Tournament in 2020. A quasi-static model is built to simulate the motion path of the bowl and predict the sinking time subsequently. The model assumes an open axisymmetric bowl with a hole in its base. The hole is modelled as a pipe for which the flow profile is governed by a modified Bernoulli’s equation which has a Coefficient of Discharge (C_d) added to account for energy losses. The motion of the entire bowl is assumed to be in quasi-static equilibrium for an infinitesimal time interval to calculate the volumetric flow rate through the hole. The model is used to predict the sinking times of various bowls against independent variables - hole radius, bowl dimensions, mass of bowl, mass distribution of bowl, and Coefficient of Discharge - and predict the motion path of bowls of different, axisymmetric geometries. Characterisation of C_d was done by draining a bowl filled with water and measuring the time taken to do so. Experimental verification was completed through measuring sinking times of 3D printed hemispherical bowls of the different variables in water. Motion tracking of bowls with different geometries was done using computational pixel tracking software to verify the model’s predictive power. Data from experiments for sinking time against the variables corroborate with the model to a great degree. The motion path tracked, matched the modelled motion path to a high degree for bowls of different shapes, namely a hemisphere, cylinder, frustum, and a free-form axisymmetric shape. The work is poised for an undergraduate level of readership.

Ocean atmospheric coupled model to estimate energy and path of cyclone near the coast

;g ns[kk x;k gS fd caxky dh [kkM+h esa vf/kdka’kr% pØokr] gjhdsu vkfn tSlh ok;qeaMyh; ifj?kVuk,¡ viuh xfr ds nk¡bZ vksj c<+rh gSaA ,lh ?kVukvksa dk v/;;u djus ds fy, geus ok;qeaMyh; xfr ;qfXer] egklkxj dh rjy xfrdh; ij fopkj fd;k gSA bl v/;;u esa geus pØokrh; ra= ds dsUnz dks fy;k gS ftlesa rjy xfrdh; lzksr rFkk FkksMh lh nwjh ij rjy xfrdh; flad gksrk gSA bl izdkj fcEc ra= ds rjy xfrdh; f}d ¼MCysV½ fufeZr gksrk gSA rnqijkar fcEc rjax vkSj mlds izfrfcEc rjax ds rjy xfrdh; f}d ¼MCysV½ ij Bksl nhokj ¼;gk¡ ij leqanz dk fdukjk½ ds laca/k esa fopkj fd;k x;kA blesa fcEc ra=] izfrfcEc ra= vkSj /kkjk xfr ls lacaf/kr fefJr fcEc ds rjy xfrdh; lehdj.k ij dk;Z fd;k x;k gSA fcEc ra=] izfrfcEc f}d ¼MCysV½ rFkk /kkjk xfr ds fefJr foHko ij bl 'kks/k i= esa fopkj fd;k x;k gSA xfr lfn’k] QyLo:i nkc dks rjy xfr ds cjukSyh ds lehdj.k dh lgk;rk ls iqu% izkIr fd;k x;kA rnqijkar leqnz ds fdukjs vFkkZr~ nhokj ij U;wure@vf/kdre nkc dh fo’ys"k.kkRed x.kuk dh xbZA vr% ;g ns[kk x;k fd pØokr vFkok gjhdsu dh ekStwnk iou vkSj ÅtkZ dqN izpfyr fLFkfr;ksa ds vk/kkj ij leqnz rV dh vksj vFkok mldh xfr ds nk¡bZ vksj tkrh gSA It is seen that in the Bay of Bengal or in the Gulf, most of the time the atmospheric phenomena, like, cyclone, hurricane etc. move towards right to its motion. To study such occurrences; we have considered fluid dynamics of ocean coupled with atmospheric motion. In the present study we have considered the eye of the cyclonic system that consist of fluid dynamical source and fluid dynamical sink at a small distance apart, and thus, constitute the fluid dynamical doublet of the object system. Then the fluid dynamical doublet of the object system and its image system has been considered with respect to a firm wall (here the sea shore). The fluid dynamical equation of complex potential with respect to the object system, the image system and the stream velocity have been undertaken. The complex potential of the object doublet, image doublet and the stream velocity have been considered. The velocity vector, consequently the pressure has been retrieve with the help of Bernoulli’s equation of fluid motion. Then the minimum /maximum pressure on the wall that is on the sea shore has been calculated analytically. Thus, it is found that on the basis of some prevailing conditions existing wind and energy the cyclone or hurricane move towards the sea coast or to the right of its motion.

Chaotic Assessment of the Heave and Pitch Dynamics Motions of Air Cushion Vehicles

In this study, three degrees of freedom nonlinear air cushion vehicle (ACV) model is introduced to examine the dynamic behavior of the heave and pitch responses in addition to the cushion pressure of the ACV in both time and frequency domains. The model is based on the compressible flow Bernoulli's equation and the thermodynamics nonlinear isentropic relations along with the Newton’s second law of translation and rotation. In this study, the dynamical investigation was based on numerical simulation using the stiff ODE solvers of the Matlab software. The chaotic investigations of the proposed model is provided using the Fast Fourier Transform (FFT), the Poincaré maps, and the regression analysis. Three control design parameters are investigated for the chaotic studies. These parameters are: ACV mass (M), the mass flowrate entering the cushion volume (m ̇_in), and the ACV base radius (r). Chaos behavior was observed for heave, and pitch responses as well as the cushion pressure.

Chaotic Assessment of the Heave and Pitch Dynamics Motions of Air Cushion Vehicles

In this study, three degrees of freedom nonlinear air cushion vehicle (ACV) model is introduced to examine the dynamic behavior of the heave and pitch responses in addition to the cushion pressure of the ACV in both time and frequency domains. The model is based on the compressible flow Bernoulli's equation and the thermodynamics nonlinear isentropic relations along with the Newton’s second law of translation and rotation. In this study, the dynamical investigation was based on numerical simulation using the stiff ODE solvers of the Matlab software. The chaotic investigations of the proposed model is provided using the Fast Fourier Transform (FFT), the Poincaré maps, and the regression analysis. Three control design parameters are investigated for the chaotic studies. These parameters are: ACV mass (M), the mass flowrate entering the cushion volume (m ̇_in), and the ACV base radius (r). Chaos behavior was observed for heave, and pitch responses as well as the cushion pressure.

First order perturbation approach for the free surface flow over a step with large Weber number

The problem of two-dimensional free surface flow of inviscid and incompressible fluid over a step is considered. The flow is assumed to be as steady and irrotational, the effect of the surface tension is considered, but the gravity force is neglected. This problem is characterized by the nonlinear condition given by Bernoulli's equation on the unknown free surface, which can be considered as part of the solution. The main purpose of this work is to give an approximate solution of this problem, by using the Hilbert transformation and the perturbation technique; the results are calculated for a large values of the Weber number and small inclination angle of the step values. These results demonstrate that the used method is easily implemented, and provides approximate solutions to these kinds of problems.

Chaotic Assessment of the Heave and Pitch Dynamics Motions of Air Cushion Vehicles

In this study, a three degrees of freedom nonlinear air cushion vehicle (ACV) model is introduced to examine the dynamic behavior of the heave and pitch responses in addition to the cushion pressure of the ACV in both time and frequency domains. The model is based on the compressible flow Bernoulli’s equation and the thermodynamics nonlinear isentropic relations along with the Newton second law of translation and rotation. In this study, the dynamical investigation was based on a numerical simulation using the stiff ODE solvers of the Matlab software. The chaotic investigations of the proposed model are provided using the Fast Fourier Transform (FFT), the Poincaré maps, and the regression analysis. Three control design parameters are investigated for the chaotic studies. These parameters are: ACV mass (M), the mass flow rate entering the cushion volume (ṁin ), and the ACV base radius (r). Chaos behavior was observed for heave, and pitch responses as well as the cushion pressure.

The Study of Electrical Energy Consumption in Cascaded Pumps for Pipeline Operations

Pumps are critical infrastructure in the Oil and Gas industry, and have been widely used in pipeline transportations of petroleum products. The electrical energy needed by a pump to meet the minimum pipeline operational requirement plays an important role in the overall cost and evaluation of pumping systems performance, which has become an important issue in pump energy management and pump station designs. This paper provides a quantitative and analytical method using Bernoulli’s equation for studying energy dependence between two pumps (Booster and Mainline pumps) in series within a pump station as a function of pump’s head, flow-rate, and density. Using actual parameters from a pump station, the derived equations are validated on four different products. The densities of products are 1000 kg/cm3, 835 kg/cm3, 800 kg/cm3 and 660 kg/cm3 for Water, Automotive Gas Oil (AGO), Dual Purpose Kerosene (DPK), and Premium Motor Spirit (PMS) respectively. The results show that the energy requirement of the Booster pump is determined by the energy demand of the Mainline pump as a function of flowrate, density and pump’s head. The study is essential for developing energy saving strategy in pipeline operations and in electrical consideration when selecting the right electric motors for pumps in pump station design.

Employing Keyed Hash Algorithm, Sequential Probability Ratio Test, and Temperature Comparison Test as Security Against Node Capture Attacks of IoT-Based WSNs

The emergence of IoT opened new opportunities for development in various fields. With all the information that it gathers, it became an interesting target for multiple attackers. Thus, this study will enforce security solutions to IoT-based devices specifically in the perception layer by incorporating a Temperature Comparison Test, Keyed Hash Algorithm and evaluating it using SPRT especially in the defense against malicious activities detected in the nodes of a network namely for Mobile and Immobile attacks. For immobile attacks, using the keyed hash algorithm and the SPRT, the hash key of the passcodes was compared to determine the safety of the nodes. Hence, from the functionality test that was conducted, and evaluating the data gathered using SPRT and Bernoulli’s equation, the reliability of the protocol to detect Immobile attacks is concluded to have a 100% detection rate. For mobile node attacks, the study assumes the environment to be under normal, warm, and cold room temperatures. where both mobile and without mobile attack is simulated, the result shows that there is only an overall 3% difference from the temperature measure by the sensor to the ambient temperature. Hence, combining these protocols that are applied in the study eliminates the single points of failure in the nodes that are either applicable only to a distributed scheme or mobility support, the study also compared the tested protocol to the other existing protocols.

Simplified Mathematical Model for Computing Draining Operations in Pipelines of Undulating Profiles with Vacuum Air Valves

The draining operation involves the presence of entrapped air pockets, which are expanded during the phenomenon occurrence generating drops of sub-atmospheric pressure pulses. Vacuum air valves should inject enough air to prevent sub-atmospheric pressure conditions. Recently, this phenomenon has been studied by the authors with an inertial model, obtaining a complex formulation based on a system composed by algebraic-differential equations. This research simplifies this complex formulation by neglecting the inertial term, thus the Bernoulli’s equation can be used. Results show how the inertial model and the simplified mathematical model provide similar results of the evolution of main hydraulic and thermodynamic variables. The simplified mathematical model is also verified using experimental tests of air pocket pressure, water velocity, and position of the water column.