Yolcu otobüslerinde seyir halinde kabin içi sıcaklık dağılımının bilgisayar destekli analizi

Abstract

SUMMARY COMPUTER AIDED ANALYSIS OF THE TEMPERATURE DISTRIBUTION INSIDE THE CABIN OF A BUS ON RIDE In this study, the temperature distribution inside the cabin of a bus on ride is calculated under different boundary conditions. First of all, a heat model based on the ` lumped capacity analysis ` that is suitable for the geometry of a bus in which the effects of the construction materials of the bus can be seen, is formed. The heat transfer between the volume elements is determined by `electrical analogy` method. After forming heat model, by obtaining the equations that describe the model, the mathematical formulation is formed. Then the first order time dependent differential equation is solved by using Gauss - Seidel iteration technique. To introduce the heat model and the mathematical formulation, a basic model that contains less volume element is designed and every step of the procedure is shown. While forming the developed model, the physical bases and the boundary conditions are examined in details. The effects of the convection coefficient, the thermal capacity, radiation, number of the passengers and the velocity of the bus are shown in the graphics. The air flow in the interior region of the bus is an important factor to define the heat convection coefficient. Because of this reason the air flow in the interior region of the bus is examined and the results are shown. By making the assumptions, an elliptical differential equation for the stream function that is solved by the finite difference methods obtained. In the interior region of the bus, for the longitunel section the streamlines are plotted and the velocities of the air flow for the grid points are calculated. By the help 94of these velocities, the heat convection between the interior region and the surfaces are calculated. The model formed is suitable not only for a bus but also for every rectangular geometry. So the model is generalized and the computer program is rewritten. By using this program, the temperature distribution for every suitable geometry can be calculated with the defined initial and boundary conditions. 95