How can CFD be used to optimise the design of an impeller?4 answersComputational fluid dynamics (CFD) simulations can be used to optimize the design of an impeller. CFD software is employed to analyze the fluid flow at the impeller and study its performance. By using CFD, the flow patterns, turbulent kinetic energy dissipation, and power consumption of impellers can be studied. CFD calculations can also be used to build a sample library of impellers and construct a nonlinear model between the geometric parameters and the aerodynamic performance. Artificial neural networks (ANN) can be trained with CFD data to evaluate the objective function and provide a quick and reliable method for impeller optimization. This method is faster and more reliable compared to traditional design methods.
How can refrigeration simulation be used to optimize the performance of a refrigerator?5 answersRefrigeration simulation can be used to optimize the performance of a refrigerator by analyzing the effects of various design and operating parameters on system efficiency and cooling performance. Through simulation, the performance of different refrigerants can be compared to identify alternatives with higher coefficients of performance (COP) and lower global warming potential (GWP). Additionally, simulation can be used to investigate the effects of design parameters such as regenerator length, displacer height, and piston diameter to stroke ratio on cooling power and COP, allowing for the proposal of optimized refrigerator designs. Furthermore, simulation can be used to analyze the temperature distribution inside storage chambers and optimize air-duct structures to improve temperature uniformity and air volume distribution. Simulation can also be used to theoretically simulate the cold storage process and design energy storage equipment to improve cold storage capacity and reduce energy loss.
What is the optimal size of a tube in tube structure?5 answersThe optimal size of a tube in tube structure depends on various factors. One study found that using tubes with a diameter of 6.35 mm can deliver about 30% more cooling capacity compared to conventional tubes with a diameter of 15.88 mm. Another study showed that even smaller diameter tubes, such as 3.175 mm, can result in an even higher increase in capacity, around 55%. However, it is important to consider wetting characteristics as tube diameter decreases, as wetting may become poorer. Additionally, the concept of tubular structures in tall buildings suggests that tube in tube structures are better compared to other tubular systems, as they have less storey shear, storey displacement, and storey drift. Therefore, the optimal size of a tube in tube structure may vary depending on the specific application and desired performance criteria.
What is the maximum speed of a high speed planing hull?5 answersThe maximum speed of a high-speed planing hull can vary depending on the design and configuration of the hull. One study found that a new wave-piercing-type high-speed planing boat reached a maximum speed of 35 knots. Another research project aimed to develop a Dynaplane hull design that would allow for speeds in excess of 50 knots. While specific maximum speeds were not mentioned in the other abstracts, they provided information on different hull designs and features, such as a hull with a substantially lowered central portionand a boat hull with demi-hulls and specific running surface configurations.
What are the factors that affect the heat transfer in a fishing vessel hold?3 answersFactors that affect heat transfer in a fishing vessel hold include hull design, resistance of appendages, fouling of the hull, machinery, propeller design, and fishing gear and methods. Additionally, the heat released from the engine exhaust gases can be utilized to power an external cooling system onboard, providing efficient refrigeration for the caught fish. The transfer of heat through the hold wall sections can also impact heat leakage through fish hold boundaries, and a finite-difference heat-transfer model has been developed to improve prediction and design curves for wall sections of steel fishing vessels.
How can I optimize the performance of a heat exchanger using COMSOL?4 answersTo optimize the performance of a heat exchanger using COMSOL, several steps can be followed. First, a computational model of the heat exchanger can be created using COMSOL Multiphysics software. This model can be used to simulate the temperature changes in the heat exchanger and analyze its performance. By modifying the geometry of the heat exchanger, its performance can be further improved. The simulation results can be compared with theoretical results to validate the model. Additionally, the effects of hot and cold fluid flow velocity on the overall heat transfer coefficient (UA) and effectiveness can be determined using the simulation. By adjusting the variables and optimizing the design using COMSOL, the performance of the heat exchanger can be enhanced.