IMPROVEMENT AND VALIDATION OF ACCURACY OF NUMERICAL SIMULATION FOR OVERFLOW FROM EMBANKMENT UNDER STEADY AND UNSTEADY FLOW CONDITION

2019 ◽  
Vol 75 (2) ◽  
pp. I_571-I_576
Author(s):  
Yoshiya IGARASHI ◽  
Yuya KIMIWADA ◽  
Norio TANAKA
Keyword(s):  
Numerical Simulation ◽  
Unsteady Flow ◽  
Flow Condition ◽  
Unsteady Flow Condition

Lift and Drag Characteristics of an Airfoil and Feedback Flow Control by Flap Actuators in the Low Reynolds Number Region

2015 ◽  
Author(s):  
Toshiki Mori ◽  
Masashi Yamaguchi ◽  
Kyoji Inaoka ◽  
Mamoru Senda
Keyword(s):  
Reynolds Number ◽  
Wind Speed ◽  
Unsteady Flow ◽  
Flow Control ◽  
Flow Condition ◽  
Low Reynolds Number ◽  
High Lift ◽  
Unsteady Flow Condition ◽  
Lift And Drag ◽  
Drag Ratio

The present paper describes the applicability of the flow control device, mini actuators attached on the leading edge of an airfoil, for the flow separation control under unsteady flow condition in the low Reynolds number region. Lift and drag have been measured for a wide variety of the wind speeds (Reynolds numbers) and the angles of attack. Then, effects of simple feedback flow control, where the time-dependent signal of the lift-drag ratio has been used as an input to detect the stall and served as a trigger to start the actuation, have been explored under the unsteady flow condition for evading the stall. For every Reynolds number from 30,000 to 80,000, the actuators worked quite well to delay the stall, increasing both in the lift and the stall angle of attack. Then, threshold value of the lift-drag ratio was determined to detect the stall. Effectiveness of the feedback control of the actuation was demonstrated under the condition of the wind speed decrease which would lead to the stall if no-actuation. Immediately after the velocity decrease, the decrease in the lift-drag ratio below the threshold were detected and the dynamic actuations were started, resulting in evading the stall and keeping high lift. The additional operation of the feedback, stopping the actuation when the lift-drag ratio showed lower than the second threshold, was revealed effective to keep the high lift force under the condition combined with the wind speed increase and decrease.

Unsteady flow condition of contra-rotating small-sized axial fan

2011 ◽  
Vol 20 (6) ◽  
pp. 495-502 ◽  
Author(s):  
T. Shigemitsu ◽  
J. Fukutomi ◽  
Y. Okabe ◽  
K. Iuchi ◽  
H. Shimizu
Keyword(s):  
Unsteady Flow ◽  
Flow Condition ◽  
Axial Fan ◽  
Unsteady Flow Condition

Experimental Investigation of Film Cooling Effectiveness of a Highly Loaded Turbine Blade Under Steady and Periodic Unsteady Flow Conditions

2016 ◽  
Author(s):  
Ali Nikparto ◽  
Meinhard T. Schobeiri
Keyword(s):  
Unsteady Flow ◽  
Turbine Blade ◽  
Film Cooling ◽  
Flow Condition ◽  
Leading Edge ◽  
Experimental Investigations ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Unsteady Flow Condition ◽  
Highly Loaded

This paper describes the experimental investigations of film cooling effectiveness on a highly loaded low-pressure turbine blade under steady and periodic unsteady wake induced flow condition. The cascade facility in Turbomachinery Performance and Flow Research Lab (TPFL) at Texas A&M University was used to simulate the periodic unsteady flow condition inside gas turbine engines. Moving wakes that are originated from upstream stator blades are simulated inside the cascade facility by moving rods in front of the blades. The flow coefficient is maintained at 0.8 and the incoming wakes have a reduced frequency of 3.18. There are a total of 617 holes on the blade, which are distributed along 13 different rows. 6 rows cover the suction side, 6 other rows cover the pressure side and one last row feeds the leading edge. Each row has a twin row on the other side of the blade with exact same number of holes and arrangement (except for leading edge). They both are connected to the same cavity. Coolant is injected from either sides of the blade through the 6 cavities to form a uniform distribution along the span of the blade. In order to study the film cooling effectiveness under periodic unsteady flow condition, the blade surfaces were covered with Pressure Sensitive Paint (PSP) and were excited with green light. Experiments were performed for Reynolds number of 150,000 and approximate blowing ratio of coolant was maintained at one, based on equal mass flux distribution, for all rows throughout the experiments. Experimental investigations were performed to determine the effect of flow separation, and pressure gradient on film-cooling effectiveness in the absence of wakes. Moreover, the effect of impinging wakes on the overall film coverage of blade surfaces was studied.

Unsteady Flow Condition of Centrifugal Pump for Low Viscous Fluid Food

2017 ◽  
Vol 10 (4) ◽  
pp. 432-438
Author(s):  
Toru Shigemitsu ◽  
Junichiro Fukutomi ◽  
Takumi Matsubara ◽  
Masahiro Sakaguchi
Keyword(s):  
Viscous Fluid ◽  
Unsteady Flow ◽  
Centrifugal Pump ◽  
Flow Condition ◽  
Unsteady Flow Condition

1316 Wells Turbine with 3-dimentional Blades : The Performance under Unsteady Flow Condition

2015 ◽  
Vol 2015.53 (0) ◽  
pp. _1316-1_-_1316-2_
Author(s):  
Manabu Takao ◽  
Katsuya Takasaki ◽  
Tomohiro Tsunematsu ◽  
Toshiaki Setoguchi
Keyword(s):  
Unsteady Flow ◽  
Flow Condition ◽  
Wells Turbine ◽  
Unsteady Flow Condition

Three step-drawdown dewatering test in unsteady flow condition: a case study of the Siwan coal mine in North China Coalfield

2018 ◽  
Vol 77 (19) ◽  
Author(s):  
Ya-zun Wu ◽  
Zi-jie Wang ◽  
Yun Lin ◽  
Chun-fang Pan ◽  
Guo-ying Pan
Keyword(s):  
Unsteady Flow ◽  
Coal Mine ◽  
Flow Condition ◽  
North China ◽  
Unsteady Flow Condition

scholarly journals Unsteady Flow Condition between Front and Rear Rotor of Contra-Rotating Small Sized Axial Fan

2017 ◽  
Vol 07 (03) ◽  
pp. 371-385 ◽  
Author(s):  
Toru Shigemitsu ◽  
Hiroaki Fukuda ◽  
Katsuhiko Hirosawa
Keyword(s):  
Unsteady Flow ◽  
Flow Condition ◽  
Axial Fan ◽  
Unsteady Flow Condition
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