Tetsuo Tagori

Turbulent measurements in the lobe mixer of a turbofan engine.

Turbofan engines may use a device known as a lobe mixer in the exhaust duct, in which the core flow and the fan flow are rapidly mixed with strong secondary flows. This mixing process provides a means of achieving significant performance gains and reducing jet noise. Although this fact has been known for some time, the details of the mixing process within the mixing duct and exhaust nozzle have not been well understood. We measured the three-dimensional turbulent flow in a scale model of an exhaust duct with a lobe mixer by using a hot-wire anemometer, and clarified, experimentally, the basic characteristics of the mixing process.

A study of flow in a solar pond under heat extracting condition.

To utilize heat energy stored in solar ponds, it is common to extract hot water from the storage layer and return it after the heat-exchange to the same layer. But the injection of the cold water causes a complex flow in the storage layer especially when the pond is heated by the sunshine at the same time.The purpose of this study is to get basic knowledge for the behavior of flow in solar ponds under heat extracting condition. For this purpose, an experimental pond was built and flow in the pond was ovserved using flow visualization technique including a Laser Light Sheet method. Thermometry over the flow field was also done.

Calculation of the flow around a passenger car by vortex lattice method.

Maneuvering stability of a passenger car is threatened when it is subjected to intensive oblique wind.In this study the flow around an automobile body in the oblique wind was carried out by numerical calculation with vortex lattice method. Visualization by the experiment with oil film method and tuft grid on a 1/8 scale model was also carried out to compare with the results of calculation. Good coincidence was obtained between the experimental results and the calculation.

Transonic flow analysis and its visualization using personal computer.

The personal computer system for analyzing compressible transonic flow and visualizing its flow field has been developed. This system solves two-dimensional Euler equation by using Beam-Warming implicit approximate factorization scheme and the resultant flow field is visualized with computer graphic techniques. This system enables us to save the fare of mainframe computers and promotes the effectiveness in developing the flow code.

Flow visualization around the forward skewed blades.

In recent years researchers have reported the ship hull vibration and the noise induced by the propeller are reduced by using the highly skewed propeller.In this investigation, a forward skewed propeller blade is tested expecting better characteristics to reduce the vibration and the noise. A protoype, a backward skewed blade and combined skew ones are tested as well.Measurements of hydrodynamical forces and flow visualizations by oil film method and tuft grid method are carried out on the blades. As a result, we found the forward skewed blade does not stall at the high attack angle and the location of the voltex from the tip of the forward skewed blade is closer to the root of the blade than that of the backward skewed blade.