scholarly journals Combustion Characteristics of Multi-Element Swirl Coaxial Jet Injectors under Varying Momentum Ratios

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4064
Author(s):  
Younseok So ◽  
Yeoungmin Han ◽  
Sejin Kwon
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Turbine Blades ◽  
Liquid System ◽  
Combustion Characteristics ◽  
Combustion Stability ◽  
Inlet Temperature ◽  
Combustion Gas ◽  
Combustion Pressure

The combustion characteristics of a staged combustion cycle engine with an oxidizer-rich preburner were experimentally studied at different momentum ratios of multi-element injectors. Propellants were simultaneously supplied as a liquid–liquid–liquid system, and an injector was designed in which a swirl coaxial jet is sprayed. The injector burned the propellants in the inner chamber which had a temperature greater than 2000 K. To cool the combustion gas, a liquid oxidizer was supplied to the cooling channel outside the injector. To prevent the turbine blades from melting, the temperature of the combustion gas was maintained below 700 K. To confirm the combustion characteristics at different momentum ratios of the high-temperature combustion gas inside the injector and the low-temperature liquid oxidizer outside the injector, three types of injectors were designed and manufactured with different momentum ratios: MR 3.0, MR 3.3, and MR 3.7. In this study, the results of the combustion test for each type were compared for 30 s. For ORPB-A, a combustion pressure of 18.5 MPaA, fuel mass flow rate of 0.26 kg/s, oxidizer mass flow rate of 15.3 kg/s, and turbine inlet temperature of 686 K were obtained in the combustion stability period of 29.0–29.5 s. The combustion efficiency was 98% for MR 3.0 (ORPB-A), which was superior to that for other momentum ratios. In addition, during the combustion test for MR 3.0, the fluctuations in the characteristic velocity, combustion pressure, and propellant mass flow rate were low, indicating that combustion was stable. The three types of combustion instability were all less than 0.8%, thus confirming that the combustion stability was excellent.

Experimental Investigation of a Pilot Compression Chiller With Alternatives Refrigerants R401a and R134a

2005 ◽  
Author(s):  
M. Fatouh
Keyword(s):  
Experimental Investigation ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Water Mass ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Chilled Water ◽  
Water Mass Flow Rate

This paper reports the results of an experimental investigation on a pilot compression chiller (4 kW cooling capacity) working with R401a and R134a as R12 alternatives. Experiments are conducted on a single-stage vapor compression refrigeration system using water as a secondary working fluid through both evaporator and condenser. Influences of cooling water mass flow rate (170–1900 kg/h), cooling water inlet temperature (27–43°C) and chilled water mass flow rate (240–1150 kg/h) on performance characteristics of chillers are evaluated for R401a, R134a and R12. Increasing cooling water mass flow rate or decreasing its inlet temperature causes the operating pressures and electric input power to reduce while the cooling capacity and coefficient of performance (COP) to increase. Pressure ratio is inversely proportional while actual loads and COP are directly proportional to chilled water mass flow rate. The effect of cooling water inlet temperature, on the system performance, is more significant than the effects of cooling and chilled water mass flow rates. Comparison between R12, R134a and R401a under identical operating conditions revealed that R401a can be used as a drop-in refrigerant to replace R12 in water-cooled chillers.

scholarly journals Analytical and Experimental Investigation of a Plate Fin Heat Exchanger at Cryogenics Temperature

2021 ◽  
Vol 39 (4) ◽  
pp. 1225-1235
Author(s):  
Ajay K. Gupta ◽  
Manoj Kumar ◽  
Ranjit K. Sahoo ◽  
Sunil K. Sarangi
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Cryogenic Temperature ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Compact Size

Plate-fin heat exchangers provide a broad range of applications in many cryogenic industries for liquefaction and separation of gasses because of their excellent technical advantages such as high effectiveness, compact size, etc. Correlations are available for the design of a plate-fin heat exchanger, but experimental investigations are few at cryogenic temperature. In the present study, a cryogenic heat exchanger test setup has been designed and fabricated to investigate the performance of plate-fin heat exchanger at cryogenic temperature. Major parameters (Colburn factor, Friction factor, etc.) that affect the performance of plate-fin heat exchangers are provided concisely. The effect of mass flow rate and inlet temperature on the effectiveness and pressure drop of the heat exchanger are investigated. It is observed that with an increase in mass flow rate effectiveness and pressure drop increases. The present setup emphasis the systematic procedure to perform the experiment based on cryogenic operating conditions and represent its uncertainties level.

scholarly journals Engine Performance of a Gardener Compression Ignition Engine using Rapeseed Methyl Esther

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Hamisu A Dandajeh ◽  
Talib O Ahmadu
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Equivalence Ratio ◽  
Engine Speed ◽  
Engine Performance ◽  
Combustion Characteristics ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Air Mass

This paper presents an experimental investigation on the influence of engine speed on the combustion characteristics of a Gardener compression ignition engine fueled with rapeseed methyl esther (RME). The engine has a maximum power of 14.4 kW and maximum speed of 1500 rpm. The experiment was carried out at speeds of 750 and 1250 rpm under loads of 4, 8, 12, 16 and 18 kg. Variations of cylinder pressure with crank angle degrees and cylinder volume have been examined. It was found that RME demonstrated short ignition delay primarily due to its high cetane number and leaner fuel properties (equivalence ratio (φ) = 0.22 at 4kg). An increase in thermal efficiency but decrease in volumetric efficiency was recorded due to increased brake loads. Variations in fuel mass flow rate, air mass flow rate, exhaust gas temperatures and equivalence ratio with respect to brake mean effective pressure at engine speeds of 750 and 1250 rpm were also demonstrated in this paper. Higher engine speed of 1250 rpm resulted in higher fuel and air mass flow rates, exhaust temperature, brake power and equivalent ratio but lower volumetric efficiency. Keywords— combustion characteristics, engine performance, engine speed, rapeseed methyl Esther

Experimental Study on the Performance of a See-Through Labyrinth Seal With Two-Phase, Mainly-Liquid Mixtures

2020 ◽  
Author(s):  
Min Zhang ◽  
Dara W. Childs
Keyword(s):  
Experimental Study ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Labyrinth Seal ◽  
Test Fluid ◽  
Inlet Temperature ◽  
Pure Liquid ◽  
Pump Rotor ◽  
Piston Seal

Abstract With the increasing demand of the oil & gas industry, many pump companies are developing multiphase pumps, which can handle liquid-gas flow directly without separating the liquid from a mixed flow. The see-through labyrinth seal is one of the popular types of non-contact annular seals that act as a balancing piston seal to reduce the axial thrust of a high-performance centrifugal pump. The see-through labyrinth seal also generates reaction forces that can significantly impact the rotordynamic performance of the pump. Multiphase pumps are expected to operate from pure-liquid to pure-gas conditions. Zhang et al. (2019) conducted a comprehensive experimental study on the performance (leakage and rotordynamic coefficients) of a see-through labyrinth seal under mainly-gas conditions. This paper continues Zhang et al.’s (2019) research and studies the performance of the see-through TOS (tooth-on-stator) labyrinth seal under mainly-liquid conditions. The test seal’s inner diameter, length, and radial clearance are 89.256 mm, 66.68 mm, and 0.178 mm, respectively. The test fluid is a mixture of air and silicone oil (PSF-5cSt), and the inlet GVF (gas volume fraction) varies from zero to 12%. Tests are conducted at an exit pressure of 6.9 bars, an inlet temperature of 39.1 °C, three pressure drops PDs (27.6 bars, 34.5 bars, and 48.3 bars), and three rotating speeds ω (5 krpm, 10 krpm, and 15 krpm). The seal is always concentric with the rotor, and there is no intentional fluid pre-rotation at the seal inlet. The air presence in the oil flow significantly impacts the leakage as well as the dynamic forces of the test seal. The first air increment (increasing inlet GVF from 0% to 3%) slightly increases the leakage mass flow rate, while further air increments steadily decrease the leakage mass flow rate. For all test conditions, the leakage mass flow rate does not change as ω increases from 5 krpm to 10 krpm but decreases as ω is further increased to 15 krpm. The reduction in the leakage mass flow rate indicates that there is an increase in the friction factor, and there could be a highly possible flow regime change as ω increases from 10 krpm to 15 krpm. For ω ≤ 10 krpm, effective stiffness Keff increases as inlet GVF increases. Keff represents the test seal’s total centering force on the pump rotor. The increase of Keff increases the seal’s centering force and would increase the pump rotor’s critical speeds. Ceff indicates the test seal’s total damping force on the pump rotor. For ω ≤ 10 krpm, Ceff first decreases as inlet GVF increases from zero to 3%, and then remains unchanged as inlet GVF is further increased to 12%. For ω = 15 krpm, Keff first increases as inlet GVF increases from zero to 3% and then decreases as inlet GVF is further increased. As inlet GVF increases, Ceff steadily decreases for ω = 15 krpm.

Flow Field in the Tip Gap of a Planar Cascade of Turbine Blades

1989 ◽  
Vol 111 (3) ◽  
pp. 276-283 ◽  
Author(s):  
M. Yaras ◽  
Yingkang Zhu ◽  
S. A. Sjolander
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Difference ◽  
Good Accuracy ◽  
Flow Direction ◽  
Turbine Blades ◽  
Rate Distribution ◽  
Velocity Magnitude ◽  
The Relationship

Measurements are presented for the flow in the tip gap of a planar cascade of turbine blades. Three clearances of from 2.0 to 3.2 percent of the blade chord were considered. Detailed surveys of the velocity magnitude, flow direction, and total pressure within the gap were supplemented by blade surface and endwall static pressure measurements. The results help to clarify the relationship between the leakage mass flow rate distribution and the driving pressure differences. It was found that even for the present relatively large clearances, fluid near the endwall experiences a pressure difference that is comparable with the blade pressure difference. It is also shown that a simple model can predict with good accuracy the mass flow rate distribution and the magnitude and direction of the velocity vectors within the gap.

Effect of Mass Flow Rate on Dryer Room Radiator Pressure Drop and Heat Transfer

2016 ◽  
Vol 836 ◽  
pp. 102-108
Author(s):  
Mirmanto ◽  
Emmy Dyah Sulistyowati ◽  
I Ketut Okariawan
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Electrical Power ◽  
Maximum Temperature ◽  
Inlet Temperature ◽  
Mass Flow Rates ◽  
Room Model

In the rainy season, in tropical countries, to dry stuffs is difficult. Using electrical power or fossil energy is an expensive way. Therefore, it is wise to utilize heat waste. A device that can be used for this purpose is called radiator. The effect of mass flow rate on pressure drop and heat transfer for a dryer room radiator have been experimentally investigated. The room model size was 1000 mm x 1000 mm x 1000 mm made of plywood and the overall radiator dimension was 360 mm x 220 mm x 50 mm made of copper pipes with aluminium fins. Three mass flow rates were investigated namely 12.5 g/s, 14 g/s and 16.5 g/s. The water temperature at the entrance was increased gradually and then kept at 80°C. The maximum temperature reached in the dryer room was 50°C which was at the point just above the radiator. The effect of the mass flow rate on the room temperature was insignificant, while the effect on the pressure drop was significant. Moreover, the pressure drop decreased as the inlet temperature increased. In general, the radiator is recommended to be used as the heat source in a dryer room.

Conjugate Flow and Heat Transfer Investigation of a Turbo Charger: Part II — Experimental Results

2003 ◽  
Author(s):  
Dieter Bohn ◽  
Norbert Moritz ◽  
Michael Wolff
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Inlet Temperature ◽  
Total Heat Flux ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Turbo Charger

In this paper the results of experimental investigations are presented that were performed at the institute’s turbo charger test stand to determine the heat flux between the turbine and the compressor of a passenger car turbo charger. A parametric study has been performed varying the turbine inlet temperature and the mass flow rate. The aim of the analysis is to provide a relation of the Reynolds number at the compressor inlet and the heat flux from the turbine to the compressor with the turbine inlet temperature as the parameter. Thereto, the analysis of the local heat fluxes is necessary which is performed in a numerical conjugate heat transfer and flow analysis which is presented in part I of the paper. Beyond the measurements necessary to determine the operating point of compressor and turbine, the surface temperature of the casings were measured by resistance thermometers at different positions and by thermography. All measurement results were used as boundary conditions for the numerical simulation, i.e. the inlet and outlet flow conditions for compressor and turbine, the rotational speed, the oil temperatures and the temperature distribution on the outer casing surface of the turbo charger. The experimental results show that the total heat flux from turbine to compressor is mainly influenced by the turbine inlet temperature. The increase of the mass flow rate leads to a higher pressure ratio in the compressor so that the compressor casing temperature is increased. Due to the turbo charger’s geometry heat radiation has a small influence on the total heat flux.

Effect of combustion gas mass flow rate on carbon/carbon composite nozzle ablation in a solid rocket motor

Carbon ◽  
2012 ◽  
Vol 50 (4) ◽  
pp. 1554-1562 ◽  
Author(s):  
Li-na Peng ◽  
Guo-qiang He ◽  
Jiang Li ◽  
Lei Wang ◽  
Fei Qin
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Carbon Composite ◽  
Rocket Motor ◽  
Solid Rocket Motor ◽  
Combustion Gas ◽  
Solid Rocket

Numerical and Experimental Investigations on Heat Transfer Phenomena of an Aluminium Microchannel Heat Sink

2011 ◽  
Vol 145 ◽  
pp. 129-133 ◽  
Author(s):  
Thanhtrung Dang ◽  
Ngoctan Tran ◽  
Jyh Tong Teng
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Sink ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Microchannel Heat Sink ◽  
Maximum Heat

The study was done both numerically and experimentally on the heat transfer behaviors of a microchannel heat sink. The solver of numerical simulations (CFD - ACE+software package) was developed by using the finite volume method. This numerical method was performed to simulate for an overall microchannel heat sink, including the channels, substrate, manifolds of channels as well as the covered top wall. Numerical results associated with such kinds of overall microchannel heat sinks are rarely seen in the literatures. For cases done in this study, a heat flux of 9.6 W/cm2was achieved for the microchannel heat sink having the inlet temperature of 25 °C and mass flow rate of 0.4 g/s with the uniform surface temperature of bottom wall of the substrate of 50 °C; besides, the maximum heat transfer effectiveness of this device reached 94.4%. Moreover, in this study, when the mass flow rate increases, the outlet temperature decreases; however, as the mass flow rate increases, the heat flux of this heat sink increases also. In addition, the results obtained from the numerical analyses were in good agreement with those obtained from the experiments as well as those from the literatures, with the maximum discrepancies of the heat fluxes estimated to be less than 6 %.

Thermo-Efficiencies of a Tubular Combustor Under Different Inlet Conditions

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Ahmet Topal ◽  
Onder Turan
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Loading Condition ◽  
Inlet Temperature ◽  
Test Rig ◽  
Aerodynamic Loading ◽  
Air Inlet ◽  
Energy And Exergy ◽  
Inlet Conditions

AbstractExergy efficiencies of the gas turbine become an important issue in recent years and by the way conducted studies regarding to this subject shows that the highest exergy destruction is observed in the combustor and afterburner modules. Therefore it is beneficial to perform analyses that are specific to the combustor exergy efficiency. This study includes the energy$\left( {{\eta _{cc}}} \right)$and exergy efficiencies$\left( {{\eta _{ex}}} \right)$(thermo-efficiencies) of a tubular combustor for different inlet conditions. Both of the first law and second law efficiencies have been performed on the experimental data and efficiency trends are investigated for changing aerodynamic conditions. Combustor tests have been conducted in an atmospheric test rig and combustor air inlet temperature$\left( {{T_{03}}} \right)$, air mass flow rate$\left( {{{\dot m}_a}} \right)$and fuel mass flow rate$\left( {{{\dot m}_f}} \right)$have been set for the pre-defined conditions. Moreover, exhaust gas emissions were measured by using a gas analyzer system. In the study, highest energy and exergy efficiencies have been obtained at minimum aerodynamic loading condition as 99.0 % and 70.2 % respectively. Moreover efficiencies have the lowest value as 92.7 % and 54.0 % at the maximum aerodynamic loading condition. To summarize, this study aims to show the energy and exergy trends by changing inlet conditions of a tubular combustor in the atmospheric test rig.

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