Determination of the Flow Rate of Liquid in a Round Tube under Conditions of Laminar Flow by Measuring the Temperature on a Heating Element at the Tube Center

摘要

A possible method of measuring the flow rate in a tube consists in placing a heating element of constant power uniform throughout the volume within the flow. Following the time relaxation of the temperature field, one must measure the temperature at one or several points. On performing this experiment for different values of flow rate, the flow rate dependence of temperature may be constructed. If this dependence permits of constructing the inverse dependence at some of the selected points, the experimental results may be used for constructing the model dependence of flow rate on temperature for some range of values of flow rate. It is further demonstrated that the most representative dependence is the flow rate dependence of temperature abaft of the heating element. The maximal heating occurs at this point; therefore, the error of temperature measurement results in the least error of determination of flow rate. In the present study, we did not consider the optimal structure and position of the heating element. For the given geometry, we only considered the idea of the possibility of determining the flow rate by measuring the temperature at points of the flow or on the heating element.