Oil Temperature Change Research Articles

Moisture, Oil and Energy Transport During Deep-Fat Frying of Food Materials

A multiphase porous media model has been developed to predict the moisture migration, oil uptake and energy transport in a food material such as a semi-dry potato during deep-fat frying. The model predictions are validated using experimental data from the literature. Spatial moisture profiles show two distinctive regions (dry or crust region near the surface and wet region in most of the core) with a sharp interface which can be referred to as the evaporation front. Spatial temperature profiles show two distinctive regions—higher but constant temperature gradient region near the surface, and lower temperature gradient region in the core. In the crust region, vapour diffusional flux is comparable with vapour convective flux. In the more moist core region, capillary flux of liquid water is comparable to the convective flux of liquid water. Therefore, all three modes of transport—diffusional, capillarity, and pressure driven (Darcy) flow are found to be important. Sensitivity of the final product moisture and temperature to changes in oil temperature, initial moisture content of the sample, thickness of the sample, and the surface heat and mass transfer coefficients are discussed.

モデル規範形適応制御理論の電気・油圧サーボシステムへの応用

The present study deals with the adaptive control of an electrohydraulic servomotor system. A model reference adaptive controller has been designed to compensate for parameter changes such as load and oil viscosity. A digital system has been adopted because the controller has to carry out a lot of multiplyinga nd integrating operations, and a discrete-time theory is used to realize the precise control. An experimental apparatus was constructed consisting of an electrohydraulic servovalve, a servocylinder, an inertial load and the adaptive controller with a microcomputer. In order to evaluate the characteristics of this system, a simplep osition feedback system was also constructed. Experiments were carried out to compare the characteristics of the system with the adaptive controller to those of the simple feedback system. Simulation was also carried out using the microcomputer to facilitate the change in the parameters. The experimental and simulation results show that the system with the adaptive controller is proved to be much better at quality of control compared to the simple position feedback system; the former system responds very quick to the signal to be tracked, independent of the changes in inertial load and oil temperature.

Effects of Oil Temperature Change in Petroleum Pipelines on Accuracy of the Leak Detection (Ⅱ）

<b>Effects of Oil Temperature Change in Petroleum Pipelines on Accuracy of the Leak Detection (Ⅱ） </b>

A Comparison of Film Temperatures and Oil Discharge Temperature for a Tilting-Pad Journal Bearing

An experimental program was conducted to relate bearing film temperatues to oil discharge temperature. Results for a five-shoe tilting-pad journal bearing show that film temperatures are substantially higher and more sensitive to load and speed changes than is discharge oil temperature. Conversely, film temperature is less sensitive to changes in flow. It was also noted that the rate of change of film temperature is significantly greater than the rate of change of discharge oil temperature when the bearing is subjected to load change, which is a desirable characteristic for a monitoring and control system. These results should provide a more rational basis for the evaluation of bearing performance when film temperatures are reported.