34 research outputs found
Studying different scenarios of operating air conditioning system in smoke management using computational fluid dynamics in naval ships
Studying different scenarios of operating air conditioning system in smoke management using computational fluid dynamics in naval ships
Since the dawn of history maritime transport was an essential part of human communication and development which mandates the rapid development of the ship industry. It was accompanied by disasters caused by several factors among them fire played an important role. Fire can cause structural damage which affects ship safety and smoke which is life threating to passengers and ship crow. Trapped smoke in ship compartments if not ventilated or released can reach higher temperatures leading to flashover situation which enable fire propagation. The FLUENT CFD calculations were performed to analyze smoke generation and propagation in closed ship compartments. The time to reach flashover is also calculated. Based on how sealed and tight the compartment is three different scenarios where studied in this analysis: running air-condition while compartment door is open, stopped air-condition while compartment door is closed, and finally running air-condition while compartment door is closed. The calculations show that, the last scenario which incorporates modified running air-condition scheme to mitigate smoke was the best scenario
Cylindrical relief texture mapping
This paper describes a new Image Based Rendering technique aimed at increasing the realism of textured
cylindrical surfaces by adding 3D details and enhancing the depth conceived by the viewer. Cylindrical relief
texture mapping extends the existing work on planar relief textures by using cylinders as warp surfaces. After
mapping the planar relief texture to a reference cylinder, cylindrical warping equations are used to generate an
intermediate image for texture mapping the reference cylinder and introducing motion parallax. The strength of
the technique is demonstrated by the visual realism provided, with examples showing how the proposed method
can be used for generating depth enhanced panoramas and improved endoscopic simulations
Second-trimester termination of pregnancy by extra-amniotic prostaglandin F2 α or endocervical misoprostol, A comparative study
Control Strategies for the DAB Based PV Interface System
<div><p>This paper presents an interface system based on the Dual Active Bridge (DAB) converter for Photovoltaic (PV) arrays. Two control strategies are proposed for the DAB converter to harvest the maximum power from the PV array. The first strategy is based on a simple PI controller to regulate the terminal PV voltage through the phase shift angle of the DAB converter. The Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) technique is utilized to set the reference of the PV terminal voltage. The second strategy presented in this paper employs the Artificial Neural Network (ANN) to directly set the phase shift angle of the DAB converter that results in harvesting maximum power. This feed-forward strategy overcomes the stability issues of the feedback strategy. The proposed PV interface systems are modeled and simulated using MATLAB/SIMULINK and the EMTDC/PSCAD software packages. The simulation results reveal accurate and fast response of the proposed systems. The dynamic performance of the proposed feed-forward strategy outdoes that of the feedback strategy in terms of accuracy and response time. Moreover, an experimental prototype is built to test and validate the proposed PV interface system.</p></div
The voltages at the terminals of the coil connecting the two bridges of the DAB, V1 and V2.
<p>The voltages at the terminals of the coil connecting the two bridges of the DAB, V1 and V2.</p
The input current I1 to the DAB converter when a resistive load is connected.
<p>The input current I1 to the DAB converter when a resistive load is connected.</p
Block diagram of the proposed feedback strategy for DAB based PV interface system.
<p>Block diagram of the proposed feedback strategy for DAB based PV interface system.</p