Single and twin ship propeller jets produce scour holes with deposition dune. The scour hole has a maximum depth at a particular length downstream within the propeller jet. Existing equations are available to predict maximum scour depth and the corre...
As global shipping accelerates toward a green and low-carbon transformation, submerged water jet propulsion has emerged as a promising alternative to traditional propellers due to its high speed efficiency, noise reduction, and adaptability. This stu...
Experiments were conducted to investigate the seabed scour holes due to the interaction between the twin-propeller jet and quay wall. Vertical quay wall was modelled by using a polyvinyl chloride (PVC) plastic plate in a water tank. The relationship...
To investigate the impact of tip clearance variation on the cavitation performance of a high-speed pump-jet propeller, Fluent software was employed for simulation calculations. The study utilized the RNG k-ε turbulence model and ZGB cavitatio...
A numerical model is presented for ship-induced sediment transport, focusing on the fundamental role of propeller jet flow. The new module has been implemented in the open-source numerical model FUNWAVE in order to reproduce the effect of the propell...
When a pump-jet propeller rotates at high speeds, a tip vortex is usually generated in the tip clearance region. This vortex interacts with the main channel fluid flow leading to the main energy loss of the rotor system. Moreover, operating at a high...
The failure of swirling ship propellers in marine environments can lead to huge repair costs. One of the main causes of such failure is when propellers tangle with vegetation, especially in shallow flow environments like ports, harbours, or shipyards...
Pump-jet propellers are currently the mainstream propulsion method for underwater vehicles, and cavitation is an important factor limiting the high speed and miniaturization of pump-jet propellers. In order to explore the cavitation performance of hi...
This study presents an experimental investigation of seabed scour in front of a quay wall due to the interaction between propeller jet flow and the wall effect. For this purpose, two propellers (Dp = 6 and 9 cm in diameter) were used, and four differ...
The water jet nozzle is a penetrating drilling tool, which sends the pumped water to the nozzle through a high-pressure hose. It can work in a variety of working environments. When it dredges the blockage in the pipeline, its structural parameters wi...
Due to the increasing depths of coal mines and the low permeability of some coal seams, conventional methods of gas drainage in underground mines are facing many problems. To improve gas extraction, a new technique using water jets to drill tree-type...
Recent events concerning jet fuel contamination of drinking water have shown that we need a better understanding of the effects of ingested jet fuel. To this end, a reproductive study with ingested jet fuel in rats was undertaken with relatively high...
The propeller jet from a ship has a significant component directed upwards towards the free surface of the water, which can be used for ice management. This paper describes a comprehensive laboratory experiment where the operational factors affecting...
This paper presents an experimental study on the characteristics of the propeller-induced flow field and its associated scour hole around a closed type quay (with a vertical quay wall). An “oblique particle image velocimetry” (OPIV) techn...
Unmanned equipment, such as unmanned underwater vehicles (UUVs) and unmanned surface vehicles (USVs), are widely used in marine science for underwater observation, rescue, military purposes, etc. However, current vehicles are not applicable in comple...
The environmental effects of ship propellers were not even close to fully examined before the current massive ships were introduced to sea trade. Larger ships, result in greater length, beam, draft and propulsion power. Of concern here is the under-k...
This study focuses on an analysis of the spray behavior, combustion, and emission characteristics of jet propellant-5 (JP-5) and biodiesel fuels with single-injection timing and multiple split injection strategies in a common rail direct injection (C...
This research investigates cavitation around a marine propeller, employing computational fluid dynamic (CFD) solvers, including an incompressible, isothermal compressible, and fully compressible flow. The investigation commenced with simulations util...
This study presents the decays of three components of velocity for a ship twin-propeller jet associated with turbulence intensities using the Acoustic Doppler Velocimetry (ADV) measurement and computational fluid dynamics (CFD) methods. Previous rese...
Most marine jet-propelled animals have low swimming efficiencies and relatively small jet orifices. Motivated by this, the present computational fluid dynamics study simulates the flow for a jet-propelled axisymmetric body swimming steadily at interm...
The aerodynamic heating of a high-speed vehicle is destined to lead to a continuous fuselage temperature rise. However, its airborne thermal load rises exponentially. This will severely limit the thermal endurance of the high-speed vehicle and the wo...
Both propeller slipstream and flap jet flow can significantly increase the aircraft lift coefficient. To establish design principles for efficient lift enhancement via jet flow under the influence of slipstream, wind tunnel experiments are conducted...
When coal bed methane (CBM) drainage boreholes cross fractured, soft, or water-swelling strata, they collapse and block frequently. Borehole blockages result in a rapid decrease in CBM extraction ability, which leads to a reduction in CBM output and...
The global control volume-based energy utilization balance for an aerospace vehicle is extended to allow for the analysis of jet-propelled vehicles. The methodology is first developed for analyzing the energy utilization and entropy generation charac...
Pump-jets have a relatively high propulsion efficiency at medium speed and in heavy-load conditions for wheeled amphibious vehicles. However, the geometry of amphibious vehicles is very special due to the installation requirements of the pump-jet, wh...
The Hyperloop system offers revolutionary transportation, aiming for near-sonic speeds in a low-pressure environment. The aerodynamic design challenges of multiple vehicles in a confined tube remain largely unexplored, particularly regarding vehicle...
The design of an aircraft’s internal structure, and therefore the appropriate choice of material type, is a direct function of the performed tasks and the magnitude and type of the acting loads. The design of a durable aircraft structure with a...
The problem of early wear diagnostics of the combined journal-and-thrust bearing of the turbo-pump unit (TPU) of the liquid-propellant rocket engine NK-33 is considered. A feature of the problem is the significant restriction on modifications of the...
For competitive reasons, inland ships as maritime ships are increasingly larger with powerful propulsive systems. The impact of this evolution on the environment is multiple. One of the major impacts is the erosion of the channel bed and the sediment...
Prediction of the maneuvering performance of autonomous underwater vehicles equipped with pump–jet propulsion remains computationally intensive when relying solely on high-fidelity computational fluid dynamics. To overcome this limitation, a su...
In this study, a jet injection propeller was designed to increase its efficiency, and the results were compared by open water tests and numerical computations. Also, the change in shape of the slit and injection volume conditions, which are difficult...
The acceleration characteristics of a water jet-propelled ship during startup are related to its performance under mooring conditions. Water jet propulsion cavitation during startup increases the vibration and noise of the whole ship. Therefore, accu...
The race for speed ruled the early Jet Age on aviation. Aircraft manufacturers chased faster and faster planes in a fight for pride and capability. In the early 1970s, dreams were that the future would be supersonic, but fuel economy and unacceptable...
As a new type of energy-containing material, Ammonium dinitramide based liquid propellant has the advantages of being green, having low toxicity, good stability, and high safety performance. Traditional catalytic combustion methods require preheating...
A jet flow mixer is a novel agitator type widely used in the industry. However, scientific research has yet to be conducted on this impeller type. In this study, six types of fluids with various properties widely used in the paint industry were chose...
To better understand the influence of swirl on the thermally-stratified near wake of a self-propelled axisymmetric vehicle, three propulsor schemes were considered: a single propeller, contra-rotating propellers (CRP), and a zero-swirl, uniform-veloc...
This paper presents the results of a comparative investigation into the effects of the ignition method on the ballistic properties of three types of propellants: a single-base propellant, a double-base propellant and a low vulnerability (LOVA) propel...
The RC propeller performance under steady and sinusoidally time-varying freestream (stream-wise or longitudinal gust) was investigated in the University of Dayton Low-Speed Wind Tunnel (UD-LSWT) in the open-jet configuration. The propellers were test...
The hydrodynamics of the waterjet-propelled ship is a challenging issue due to the sophistication of waterjet system geometry as well as waterjet–hull interaction. In current study, three different propulsion models, namely, multiple reference...
By its nature, plasma spraying is a rapid solidification process in which finely powdered material injected into a plasma jet is almost instantly melted and propelled with high velocity, created by a strong magnetohydrodynamic force against a suitabl...
Pump-jet propulsion, a new propulsion technology, is primarily designed for underwater vehicles. Because of its concealment and excellent performance, it has been widely used, but due to its confidentiality and complexity, few studies have been publi...
Microwave ignition has attracted much attention due to its advantages of reliable ignition, large ignition area and cold-start capability. In this paper, the experimental method is used to explore the ignition ability of the microwave device to ADN-b...
Compared with traditional propellers, the pump jet has the characteristics of low noise, large thrust, and high efficiency, which is widely used in underwater ships, unmanned underwater vehicles, and underwater rescue equipment. It is difficult to de...
Tree-type drilling is a new technique for drilling radial tree-type boreholes in coal seams in underground mines using water jets to break the coal. The aim is to drain gas from the coal seams in larger quantities and from larger areas than can be do...
Wavelet transform has become a common tool for processing non-stationary signals in many different fields. The present paper reports a review of some applications of wavelet in aeroacoustics with a special emphasis on the analysis of experimental dat...
This work investigates the influence of ground effect on the performance of a UAV propeller through a combined experimental, analytical, and numerical approach. A dedicated test bench was designed and constructed to enable controlled measurements of...
Strong nonlinearity and the relevance of time-varying dynamic parameters in the maneuverable process of water-jet propulsion were major problems encountered in the prediction of variable acceleration dynamics characteristics. The relationships betwee...
The increasing demand for high energy density fuels and the concern for their safety have propelled research in the field of gelled propellants, where understanding the combustion of single gelled fuel droplets is the first stage to predict the spray...
Visualization methods have always been used to inspect flows that are invisible to the naked eye. Seedless velocimetry has been regarded as an alternative to other intrusive quantitative methods and adapted to fit many applications in the industrial...
In this paper, the flow characteristics of a continuous-type liquid–liquid pintle injector are described, focusing on the differential impact of a non-uniform center-flow distribution on single- and bi-injection methodologies as well as the cav...
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