以通过控制体的体积流量为时间上的控制体流量，以通过右边的体积流量为泰勒

Let the volume flow through the control volume be the control volume flow in time and the volume flow through the right side be the Taylor expansion formula. According to the conservation of weight, P——fluid density, g / cm3; T is the time unit, second; The velocity x, y, and z of The component point to the formula 4-2. The field theory symbolic expression is:  <br> <br>If the fluid is Incompressible: It is a constant. The formula above is simplified as follows: The <br> <br>application range of formula (4-3) is not limited. It can be used for compressible and incompressible fluids, viscous or non-viscous fluids, fixed instability, etc. flows,  <br> <br>4.2 Basic theory of <br>injection molding The injection molding process includes: preparation before molding, injection molding process and post-plastic parts deal with. This section mainly describes the filling, pressure and cooling process. <br>(1) Simplify the flow at the filling stage as: <br>1) The melt is incompressible flow; <br>2) The specific heat capacity and thermal conductivity during the filling process are constant;

The control body flow is carried out for Taylor by the volume flow of the control body as the time. According to weight conservation, P- fluid density, g/cm3; The component's velocity x, y, and z-pointing 4-2 field symbol expressions are:<br> <br>If the fluid is incompressible: is constant, on , the formula is simplified to the following:<br> <br>there are no restrictions on the scope of application of the formula (4-3). It can be used for compressible and non-compressible fluids, sticky or non-sticky fluids, fixed imstability, etc. flows,<br> <br>4.2 Basic Theory of Injection Forming<br>The injection molding process includes pre-molding preparation, injection molding and post-treatment of plastic parts. This section mainly describes the filling, pressure and cooling processes.<br>(1) Simplify the flow of the filling phase to:<br>1) The melt is incompressible;<br>2) The heat tolerance and thermal conductivity in the filling process are constant;

The volume flow through the control volume is the control volume flow in time, and the volume flow through the right side is the Taylor expansion formula. According to the conservation of weight, p-fluid density, g / cm3; t-is the unit of time, second; the velocity of the component X, y, and z-directional equation 4-2 is expressed as <br>If the fluid is incompressible: it is a constant, the formula is simplified as follows:<br>Formula (4-3) has no limitation on its application. It can be used for compressible and incompressible flows, viscous or non viscous flows, fixed instability and so on<br>4.2 basic theory of injection molding<br>The process of injection molding includes preparation before molding, injection molding process and post-processing of plastic parts. This section mainly describes the filling, pressure and cooling process.<br>(1) The flow in filling stage is simplified as follows:<br>1) The melt flow is incompressible;<br>2) The specific heat capacity and thermal conductivity are constant in the filling process;