نشریه مهندسی دریا (May 2021)
Increasing heat transfer rate in heat exchanger of underwater vehicle motor by increasing fluid flow turbulence
Abstract
Due to limited space and energy, increasing the performance of the underwater marine vehicle motor is one of the most important parameters in the design process. Increasing the performance of the underwater marine vehicle motor is directly related to increasing the efficiency of its cooling heat exchanger. In this paper, the aim is to use the geometric changes of the fins and increase the contact surface between the heat exchanger and the passing fluid in order to increase the turbulence of the flow to increase the efficiency of the heat exchanger. The existing experimental heat transfer relations have been used to validate the numerical solution method. Ansys fluent software has been used for numerical simulation. In this simulation, the pressure-based solver is used to solve the Navier Stokes equations along with the RNG k-ε turbulent model, and the solution is intended steady with air as working fluid. The effect of fluid flow velocity on circular fines at three different velocities has been investigated and then the effect of geometric changes of teeth has been evaluated in the speed of 3.0428 m / s. In the case of circular fins, the increase of fluid velocity increases heat transfer, and in the case of toothed fin, increasing the height of the teeth causes a slight increase in heat transfer and pressure drop, but as the number of teeth increases, the Nusselt number and pressure drop decrease significantly.
