Thermal Separation in 2D Vortex Tube for a Different Tube Length and Cold Mass Flow Ratio

The flow within a centrifugal rotor has strong characteristics of three-dimensional effect. A procedure called “stream-surface coordinates iteration” for the calculation of complete three dimensional flow in turbo-machinery is first described. Splitter blade techniques have been used in many rotors, especially in centrifugal compressors and pumps with high flow capacity. The difficulty of the calculation of the flow field for this type of rotor lies on that the mass flow ratio between the two sub-channels is unknown for the given total flow capacity. In the second part of this paper, an assumption about how to determine this mass flow ratio and a procedure to calculate the complete three-dimensional flow are presented. Finally, some design criteria about the splitter blades are put forward. Experimental data from two centrifugal pump impellers equipped with different splitter blades are also given to demonstrate the availability of the present calculation method.

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The Tip Leakage Flow of an Unshrouded High Pressure Turbine Blade With Tip Cooling

Journal of Turbomachinery ◽

10.1115/1.4001174 ◽

2011 ◽

Vol 133 (4) ◽

Cited By ~ 19

Author(s):

Chao Zhou ◽

Howard Hodson

Keyword(s):

Mass Flow ◽

Suction Side ◽

Aerodynamic Performance ◽

Flow Ratio ◽

Tip Leakage Flow ◽

Momentum Exchange ◽

Leakage Loss ◽

Tip Leakage ◽

Lower Loss ◽

Mass Flow Ratio

Experimental, analytical, and numerical methods have been employed to study the aerodynamic performance of four different cooled tips with coolant mass ratios between 0% and 1.2% at three tip gaps of 1%, 1.6%, and 2.2% of the chord. The four cooled tips are two flat tips with different coolant holes, a cooled suction side squealer tip and a cooled cavity tip. Each tip has ten coolant holes with the same diameter. The uncooled cavity tip produces the smallest loss among all uncooled tips. On the cooled flat tip, the coolant is injected normally into the tip gap and mixes directly with flow inside the tip gap. The momentum exchange between the coolant and the flow that enters the tip gap creates significant blockage. As the coolant mass flow ratio increases, the tip leakage loss of the cooled flat tip first decreases and then increases. For the cooled cavity tip, the blockage effect of the coolant is not as big as that on the cooled flat tip. This is because after the coolant exits the coolant holes, it mixes with flow in the cavity first and then mixes with tip flow in the tip gap. The tip leakage loss of the cooled cavity tip increases as the coolant mass flow ratio increase. As a result, at a tip gap of 1.6% of the chord, the cooled cavity tip gives the lowest loss. At the smallest tip gap of 1% of the chord, the cooled flat tip produces less loss than the cooled cavity tip when the coolant mass flow ratios larger than 0.23%. This is because with the same coolant mass flow ratio, a proportionally larger blockage is created at the smallest tip gap. At the largest tip gap of 2.2% of the chord, the cavity tip achieves the best aerodynamic performance. This is because the effect of the coolant is reduced and the benefits of the cavity tip geometry dominate. At a coolant mass flow ratio of 0.55%, the cooled flat tips produce a lower loss than the cavity tip at tip gaps less than 1.3% of the chord. The cooled cavity tip produces the least loss for tip gaps larger than 1.3% of the chord. The cooled suction side squealer has the worst aerodynamic performance for all tip gaps studied.

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Numerical study on increasing mass flow ratio by energy deposition of high frequency pulsed laser

High Power Laser and Particle Beams ◽

10.3788/hplpb20132507.1715 ◽

2013 ◽

Vol 25 (7) ◽

pp. 1715-1718 ◽

Cited By ~ 1

Author(s):

王殿恺 Wang Diankai ◽

洪延姬 Hong Yanji ◽

李倩 Li Qian

Keyword(s):

Mass Flow ◽

High Frequency ◽

Energy Deposition ◽

Numerical Study ◽

Pulsed Laser ◽

Flow Ratio ◽

Mass Flow Ratio

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Flow Characteristics of Fluid Droplet Obtained From Air Assisted Atomizer

ASME-JSME-KSME 2011 Joint Fluids Engineering Conference: Volume 2, Fora ◽

10.1115/ajk2011-31013 ◽

2011 ◽

Cited By ~ 2

Author(s):

Pipatpong Watanawanyoo ◽

Hirofumi Mochida ◽

Hiroyuki Hirahara ◽

Sumpun Chaitep

Keyword(s):

Mass Flow ◽

Cone Angle ◽

Flow Ratio ◽

Test Liquid ◽

Solid Cone ◽

Spray Cone ◽

Supply Pressure ◽

Liquid Mass ◽

Air Supply ◽

Mass Flow Ratio

Air assisted atomizer system was designed and developed for fuel injection. The present purpose is to utilize a low pressure in supplying of atomized fuel. Distilled water was used as test liquid on the experiments for the system of atomization. The results revealed air assisted atomizer had a capability to inject the test liquid in the range of the rates of 0.0019–0.00426 kg/s, with the use of air pressure supplied from 68.9 to 689 kPa. In this research, the test liquid supply pressure was kept constant and the air flow rate through the atomizer was varied over a range of air supply pressure to obtain the variation in air liquid mass flow ratio (ALR). The spray solidity was studied by taking pictures of the spray at different liquid air supply pressures. The experimental investigations suggest that spray cone angle tends to increase with increasing in air liquid mass flow ratio because the kinetic energy of the flow keeps on increasing. The solid cone spray has a pattern of penetration depth between 408–446 mm. and cone angle between 14.5–23.6°. It was observed that spray formed the solid cone at all the operating conditions.

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Numerical Investigation of the Effect of Inlet Flow Angle on Film Cooling Performance for the Blade Tip With Suction Surface Squealer Rim

Volume 5A: Heat Transfer ◽

10.1115/gt2019-91104 ◽

2019 ◽

Author(s):

Zhiqiang Yu ◽

Jianjun Liu ◽

Chen Li ◽

Baitao An

Keyword(s):

Mass Flow ◽

Film Cooling ◽

Incidence Angle ◽

Leading Edge ◽

Flow Ratio ◽

Suction Surface ◽

Cooling Performance ◽

Tip Leakage ◽

Pressure Surface ◽

Mass Flow Ratio

Abstract Numerical investigations have been performed to study the effect of incidence angle on the aerodynamic and film cooling performance for the suction surface squealer tip with different film-hole arrangements at τ = 1.5% and BR = 1.0. Meanwhile, the full squealer tip as baseline is also investigated. Three incidence angles at design condition (0 deg) and off-design conditions (± 7 deg) are investigated. The suction surface, pressure surface, and the camber line have seven holes each, with an extra hole right at the leading edge. The Mach number at the cascade inlet and outlet are 0.24 and 0.52, respectively. The results show that the incidence angle has a significant effect on the tip leakage flow characteristics and coolant flow direction. The film cooling effectiveness distribution is altered, especially for the film holes near the leading edge. When the incidence angle changes from +7 deg to 0 and −7 deg, the ‘re-attachment line’ moves downstream and the total tip leakage mass flow ratio decreases, but the suction surface tip leakage mass flow ratio near leading edge increases. In general, the total tip leakage mass flow ratio for suction surface squealer tip is 1% greater than that for full squealer tip at the same incidence angle. The total pressure loss coefficient of suction surface squealer tip is larger than that for full squealer tip. The full squealer tip with film holes near suction surface and the suction surface squealer tip with film hole along camber line show high film cooling performance, and the area averaged film cooling effectiveness at positive incidence angle +7 deg is higher than that at 0 and −7 deg. The coolant discharged from film holes near pressure surface only cools narrow region near pressure surface.

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Leading Edge Film Cooling Effects on Turbine Blade Heat Transfer

Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration ◽

10.1115/95-gt-275 ◽

1995 ◽

Cited By ~ 1

Author(s):

Vijay K. Garg ◽

Raymond E. Gaugler

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Transfer Coefficient ◽

Mass Flow ◽

Film Cooling ◽

Three Dimensional ◽

Stagnation Temperature ◽

Flow Ratio ◽

Adiabatic Effectiveness ◽

Mass Flow Ratio

An existing three-dimensional Navier-Stokes code (Arnone et al., 1991), modified to include film cooling considerations (Garg and Gaugler, 1994), has been used to study the effect of spanwise pitch of shower-head holes and coolant to mainstream mass flow ratio on the adiabatic effectiveness and heat transfer coefficient on a film-cooled turbine vane. The mainstream is akin to that under real engine conditions with stagnation temperature = 1900 K and stagnation pressure = 3 MPa. It is found that with the coolant to mainstream mass flow ratio fixed, reducing P, the spanwise pitch for shower-head holes, from 7.5 d to 3.0 d, where d is the hole diameter, increases the average effectiveness considerably over the blade surface. However, when P/d = 7.5, increasing the coolant mass flow increases the effectiveness on the pressure surface but reduces it on the suction surface due to coolant jet lift-off. For P/d = 4.5 or 3.0, such an anomaly does not occur within the range of coolant to mainstream mass flow ratios analyzed. In all cases, adiabatic effectiveness and heat transfer coefficient are highly three-dimensional.

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Compressible Flow Ejectors: Part II—Flow Field Measurements and Analysis

Journal of Fluids Engineering ◽

10.1115/1.3447153 ◽

1974 ◽

Vol 96 (3) ◽

pp. 282-288 ◽

Cited By ~ 12

Author(s):

K. R. Hedges ◽

P. G. Hill

Keyword(s):

Experimental Study ◽

Mach Number ◽

Mass Flow ◽

Field Measurements ◽

Flow Ratio ◽

Flow Rates ◽

Jet Mixing ◽

Mass Flow Rates ◽

Exit Mach Number ◽

Mass Flow Ratio

An experimental study has been made of compressible jet mixing in an axisymmetric ejector of converging-diverging geometry. The mass flow ratio was in the range 1.3 to 2.6 and the nozzle exit Mach number was 1.82. Ejector performance characteristics were obtained as well as measurements of pressure and velocity distribution over a range of mass flow rates. The experimental results were used to test the reliability of the analytical model of the flow described in Part I of the paper.

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Preliminary Experimental Study on Pressure Loss Coefficients of Exhaust Manifold Junction

International Journal of Rotating Machinery ◽

10.1155/2014/316498 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10

Author(s):

Xiao-lu Lu ◽

Kun Zhang ◽

Wen-hui Wang ◽

Shao-ming Wang ◽

Kang-yao Deng

Keyword(s):

Mass Flow ◽

Pressure Loss ◽

Total Pressure ◽

Loss Coefficient ◽

Total Pressure Loss ◽

Flow Ratio ◽

Pressure Loss Coefficient ◽

Loss Coefficients ◽

Total Pressure Loss Coefficient ◽

Mass Flow Ratio

The flow characteristic of exhaust system has an important impact on inlet boundary of the turbine. In this paper, high speed flow in a diesel exhaust manifold junction was tested and simulated. The pressure loss coefficient of the junction flow was analyzed. The steady experimental results indicated that both of static pressure loss coefficientsL13andL23first increased and then decreased with the increase of mass flow ratio of lateral branch and public manifold. The total pressure loss coefficientK13always increased with the increase of mass flow ratio of junctions 1 and 3. The total pressure loss coefficientK23first increased and then decreased with the increase of mass flow ratio of junctions 2 and 3. These pressure loss coefficients of the exhaust pipe junctions can be used in exhaust flow and turbine inlet boundary conditions analysis. In addition, simulating calculation was conducted to analyze the effect of branch angle on total pressure loss coefficient. According to the calculation results, total pressure loss coefficient was almost the same at low mass flow rate of branch manifold 1 but increased with lateral branch angle at high mass flow rate of branch manifold 1.

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