Computational fluid dynamic simulation of airfoils in unsteady low Reynolds number flows

Computational fluid dynamic simulation of airfoils in unsteady low Reynolds number flows

Computational fluid dynamic simulation of airfoils in unsteady low Reynolds number flows

Computational fluid dynamic simulation of airfoils in unsteady low Reynolds number flows

Computational fluid dynamic simulation of a pulse-width modulated spray nozzle

Computational fluid dynamics (CFD) is a useful tool used by engineers in many industries to study fluid flow. A relatively new industry to adopt the use of CFD is the agricultural industry. A spray nozzle commonly used in agricultural spraying, the Teejet 110-degree nozzle (TeeJet Technologies, 2020), was simulated. A method was developed to pulse the spray. A user-defined function was used to define the velocity at the inlet of the nozzle to pulse the spray. The domain was then extended to allow the examination of a slice 20 inches below the nozzle. The simulation results were compared to experimental results collected from a sprayer testbed. The effect of frequency was then investigated by changing the frequency of the pulses. Results from these studies show that a userdefined function can be used to pulse the spray. CFD can be used to model spray nozzles, but the validity of the results are strongly related to the computational resources available, and increasing the frequency of the pulses results in a higher concentrated spray toward the center of the spray plume. The simulations were carried out using a commercial code (CD-Adapco, 2019).

Computational Fluid Dynamics: Flow Field of an Impeller

<p class="Abstract"><em><span lang="EN-US">This paper aims to develop a centrifugal pump with variable speed controlled by inverter to adjust the flow and the head by the operator and to observe the velocity profile and pressure distribution by using computational fluid dynamic simulation program using Pheonics software. According to the simulation results, the researchers concluded that the pressure increases gradually from impeller inlet to impeller outlet and centrifugal pumps have reasonable price and maintenance as well as high efficiency comparing to the price and been more advanced by coating the inner surfaces with anti-corrosion and smooth material to reduce the friction and raise the efficiency. </span></em></p>

The inlet flow structure of a conceptual open-nose supersonic drone

This study describes the aerodynamic efficiency of a forebody–inlet configuration and computational investigation of a drone system, capable of sustainable supersonic cruising at Mach 1.60. Because the whole drone configuration is formed around the induction system and the design is highly interrelated to the flow structure of forebody and inlet efficiency, analysis of this section and understanding its flow pattern is necessary before any progress in design phases. The compression surface is designed analytically using oblique shock patterns, which results in a low drag forebody. To study the concept, two inlet–forebody geometries are considered for Computational Fluid Dynamic simulation using ANSYS Fluent code. The supersonic and subsonic performance, effects of angle of attack, sideslip, and duct geometries on the propulsive efficiency of the concept are studied by solving the three-dimensional Navier–Stokes equations in structured cell domains. Comparing the results with the available data from other sources indicates that the aerodynamic efficiency of the concept is acceptable at supersonic and transonic regimes.

Simulation of Hydraulic Cylinder Cushioning

The internal cushioning systems of hydraulic linear actuators avoid mechanical shocks at the end of their stroke. The design where the piston with perimeter grooves regulates the flow by standing in front of the outlet port has been investigated. First, a bond graph dynamic model has been developed, including the flow throughout the internal cushion design, characterized in detail by computational fluid-dynamic simulation. Following this, the radial movement of the piston and the fluid-dynamic coefficients, experimentally validated, are integrated into the dynamic model. The registered radial movement is in coherence with the significant drag force estimated in the CFD simulation, generated by the flow through the grooves, where the laminar flow regime predominates. Ultimately, the model aims to predict the behavior of the cushioning during the movement of the arm of an excavator. The analytical model developed predicts the performance of the cushioning system, in coherence with empirical results. There is an optimal behavior, highly influenced by the mechanical stress conditions of the system, subject to a compromise between an increasing section of the grooves and an optimization of the radial gap.