This paper describes the directional stability of the tumbling plate by measuring the trajectory of a paper piece that is shaped systematically. The tumbling phenomenon is considered to be an important phenomenon for aircraft flight safety because of the possibility of falling objects from the aircraft reaching far away. Therefore, this paper presents the result of measuring the trajectory of six configurations which shows that Concave configurations have directional stability while the Convex and Rectangular configurations are unstable. For generalization, the experimental result deducted using generalized equations into dimensionless values. Qualitative consideration is given to the relationship between the stall delay caused by sudden pitch motion and the phenomenon of the increase in the maximum vertical force coefficient (so-called Dynamic Lift), and the consistency with the dynamic lift wind tunnel test is shown.

Local endwall heat transfer characteristics and overall pressure loss of normal and inclined pin fins arrayed in rectangular ducts with flat and wavy endwalls have been investigated to improve the cooling efficiency of jet engine combustor liners. The detailed time-mean local Nusselt number profiles were measured using a naphthalene sublimation method based on the heat/mass transfer analogy. Four kinds of angled pin fins (−45, 0, and +45 deg with a flat endwall, and −45 deg with a wavy endwall) were tested and compared with each other. As a result, the average heat transfer coefficient on the flat endwall of normal pin fins was higher than that of the angled pin fins. The average heat transfer coefficient of −45-deg inclined pin fins with a wavy endwall is the same or a little higher than the heat transfer coefficient of those with a flat endwall; however, the pressure loss of the −45-deg inclined pin fins with a wavy endwall is less than the pressure loss of those with a flat endwall. Corresponding numerical simulations using large eddy simulation (LES) with the mixed time scale (MTS) model have been also conducted at Red = 1000 for fully developed regions, and the results have shown good quantitative agreement with mass transfer experiments. It can be concluded that wavy endwalls can realize better heat transfer with less pressure loss as long as the aim consists in enhancing endwall heat transfer in inclined pin-fin channels.

A new wind tunnel test method is proposed to measure the aerodynamic forces act on the tumbling plate and the tension of the tow string in the wind tunnel not by using force sensors but by measuring the tow position. The tumbling phenomenon is considered to be an important phenomenon for aircraft flight safety because of the possibility of falling objects from aircrafts reaching far away or for knowing the behavior of falling roof tiles blown off by strong winds. Therefore, many tests to measure the force act on the tumbling plate in wind tunnel have been conducted. However, since the rotation of the test piece is accompanied by difficulties ex. support interference, movement restrictions, etc. However, according to present method, the aerodynamic forces act on the tumbling plate in wind tunnel can be measured optically in a non-contact manner, and an expensive force sensor is not required. Furthermore, it is also effective under conditions such as low wind velocity, in which the aerodynamic forces are buried in the measurement accuracy of the force sensors. This paper explains this wind tunnel test method from the viewpoint of dynamic balance and reports the results of verification wind tunnel test in which the effectiveness of this method was confirmed.

Local endwall heat transfer characteristics and overall pressure loss of normal and inclined pin fins arrayed in rectangular ducts with flat and wavy endwalls have been investigated to improve the cooling efficiency of jet engine combustor liners. The detailed time-mean local Nusselt number profiles were measured using a naphthalene sublimation method based on the heat/mass transfer analogy. Four kinds of angled pin fins (−45, 0, and +45 degrees with a flat endwall, and −45 degrees with a wavy endwall) were tested and compared with each other. As a result, the average heat transfer coefficient on the flat endwall of normal pin fins was higher than that of the angled pin fins. The average heat transfer coefficient of −45-degree inclined pin fins with a wavy endwall is the same or a little higher than the heat transfer coefficient of those with a flat endwall; however, the pressure loss of the −45-degree inclined pin fins with a wavy endwall is less than the pressure loss of those with a flat endwall. Corresponding numerical simulations using Large Eddy Simulation (LES) with the Mixed Time Scale (MTS) model have been also conducted at Red = 1000 for fully developed regions, and the results have shown good quantitative agreement with mass transfer experiments. It can be concluded that wavy endwalls can realize better heat transfer with less pressure loss as long as the aim consists in enhancing endwall heat transfer in inclined pin-fin channels.

Endwall heat transfer characteristics of inclined pin-fin array channels have been investigated to improve the cooling efficiency of gas turbine's combustor liners. The time-mean local Nusselt number profiles were obtained by naphthalene sublimation teehnique based on the heatimass transfer analogy.Three kinds of angled pin-fins (-45, O and +45 degrees) were tested and compared with each other. As a result, the average heat transfer coefficient on the endwall ofnormal pin fins was higher than that ofthe angled pin fins.However, the total amount of heat transfer is expected to be increased by inclined pin fins because the total surface area is about 1.4 times larger than that ofnorrnal pin fins, and the pressure loss in angled pin-fui channel was smaller than in the normal pin-fin chamel,