| 摘要 |
PURPOSE:To measure wind pressure accurately without using a detector which detects a burble phenomenon by calculating the standard deviation of sampling data on the wind pressure due to a pitot pipe and using it for decision making when the wind pressure of a model of a vehicle is measured. CONSTITUTION:The model of the automobile is put in a wind tunnel and the pitot pipe is moved around the model to obtain sampling data on the air pressure. At this time, the burble phenomenon occurs at a measurement point after the pitot pipe moves. Then, sampling data are obtained at numbers of measurement points for the wind pressure of the pitot pipe to calculate the standard deviation deltat. When the wind flows uniformly without any burble phenomenon, the standard deviation deltamu of the wind pressure data is inputted to a decision means previously. When the measured standard deviation deltat is smaller than a decision level 3deltamu, the decision means decides that no burble phenomenon occurs and the measurement, is normal, and also calculates the means value. Further, wnen the measured standard deviation is larger than 3deltamu, the data are sampled again a specific time later. Thus, it is decided whether the burble phenomenon occurs from the standard deviation, so the wind pressure is measured precisely. |
