Development of low-cost test techniques for advancing film cooling technology

1987 ◽  
Author(s):  
F. SOECHTING ◽  
K. LANDIS ◽  
R. DOBROWOLSKI
Keyword(s):  
Film Cooling ◽  
Low Cost ◽  
Cooling Technology

scholarly journals Encapsulation of Active Pharmaceutical Ingredients in Lipid Micro/Nanoparticles for Oral Administration by Spray-Cooling

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1186
Author(s):  
Carmen S. Favaro-Trindade ◽  
Fernando E. de Matos Junior ◽  
Paula K. Okuro ◽  
João Dias-Ferreira ◽  
Amanda Cano ◽  
...  
Keyword(s):  
Oral Administration ◽  
Raw Materials ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Spray Cooling ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
Taste And Odor ◽  
Cooling Technology ◽  
Simple Technology

Nanoencapsulation via spray cooling (also known as spray chilling and spray congealing) has been used with the aim to improve the functionality, solubility, and protection of drugs; as well as to reduce hygroscopicity; to modify taste and odor to enable oral administration; and many times to achieve a controlled release profile. It is a relatively simple technology, it does not require the use of low-cost solvents (mostly associated to toxicological risk), and it can be applied for lipid raw materials as excipients of oral pharmaceutical formulations. The objective of this work was to revise and discuss the advances of spray cooling technology, with a greater emphasis on the development of lipid micro/nanoparticles to the load of active pharmaceutical ingredients for oral administration.

Low-Cost Cooling Technology to Reduce Postharvest Losses in Horticulture Sectors of Rwanda and Burkina Faso

2021 ◽  
pp. 183-210
Author(s):  
Eric Verploegen ◽  
Mandeep Sharma ◽  
Rashmi Ekka ◽  
Gurbinder Gill
Keyword(s):  
Burkina Faso ◽  
Low Cost ◽  
Postharvest Losses ◽  
Cooling Technology

Exploring Conjugate CFD Heat Transfer Characteristics for a Film-Cooled Flat Plate and 3-D Turbine Inlet Vane

2012 ◽  
Author(s):  
J. J. Johnson ◽  
P. I. King ◽  
J. P. Clark ◽  
P. J. Koch
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Film Cooling ◽  
Low Cost ◽  
Full Scale ◽  
Design Flow ◽  
Navier Stokes ◽  
Cooling Performance ◽  
Cooling Design ◽  
Computational Fluid Dynamics Cfd

As part of a thorough benchmarking of the baseline cooling design in planned optimization work, Reynolds-Averaged Navier Stokes (RANS) conjugate heat transfer (CHT) computational fluid dynamics (CFD) assessments have been accomplished at RTV design flow conditions to simulate both a cooled flat plate pressure side (PS) model infrared thermography experiment as well as a full-scale, fully-cooled, full-wheel blowdown experiment on the same high pressure turbine (HPT) vane. Numerous past works on turbomachinery film cooling have been conducted using flat plate models because of their simplicity, repeatability, and low cost of experimentation relative to full scale rotating blowdown rigs. Some of these works generated film cooling correlations still in use today in industry for HPT components. The CFD assessments in this work provide insight into the fundamental differences between a flat plate model and a realistic 3-D vane in terms of film cooling performance for the same PS cooling array. The comparisons of results wring out expected differences between the geometries due to aspects such as highly curved surfaces and endwall effects. However, with nearly-matched coolant-to-mainstream temperature and pressure ratios, the cooling performance between the two models is surprisingly similar, especially in the midspan region. The similarities and differences observed herein represent the rigor and accuracy afforded by simulating both the solid and fluid domains as well as the high-density unstructured meshes that take into account all individual cooling passages and internal plenums, on top of the typically-assessed external fluid flow field.

Performance of Public Film Cooling Geometries Produced Through Additive Manufacturing

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Jacob C. Snyder ◽  
Karen A. Thole
Keyword(s):  
Additive Manufacturing ◽  
Film Cooling ◽  
Gas Turbines ◽  
Nickel Alloys ◽  
Cooling Effectiveness ◽  
Powder Bed ◽  
The Public ◽  
Hot Gas ◽  
Cooling Hole ◽  
Cooling Technology

Abstract Film cooling is an essential cooling technology to allow modern gas turbines to operate at high temperatures. For years, researchers in this community have worked to improve the effectiveness of film cooling configurations by maximizing the coolant coverage and minimizing the heat flux from the hot gas into the part. Working toward this goal has generated many promising film cooling concepts with unique shapes and configurations. However, until recently, many of these designs were challenging to manufacture in actual turbine hardware due to limitations with legacy manufacturing methods. Now, with the advances in additive manufacturing, it is possible to create turbine parts using high-temperature nickel alloys that feature detailed and unique geometry features. Armed with this new manufacturing power, this study aims to build and test the promising designs from the public literature that were previously difficult or impossible to implement. In this study, different cooling hole designs were manufactured in test coupons using a laser powder bed fusion process. Each nickel alloy coupon featured a single row of engine scale cooling holes, fed by a microchannel. To evaluate performance, the overall cooling effectiveness of each coupon was measured using a matched Biot test at engine relevant conditions. The results showed that certain hole shapes are better suited for additive manufacturing than others and that the manufacturing process can cause significant deviations from the performance reported in the literature.

Highest-Efficient Film Cooling by Improved NEKOMIMI Film Cooling Holes: Part 1 — Ambient Air Flow Conditions

2013 ◽  
Author(s):  
Karsten Kusterer ◽  
Nurettin Tekin ◽  
Frederieke Reiners ◽  
Dieter Bohn ◽  
Takao Sugimoto ◽  
...  
Keyword(s):  
Film Cooling ◽  
Gas Turbines ◽  
Air Flow ◽  
Ambient Air ◽  
Flow Conditions ◽  
Test Rig ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Cooling Technology ◽  
Cooling Air

In modern gas turbines, the film cooling technology is essential for the protection of the hot parts, in particular of the first stage vanes and blades of the turbine, against the hot gases from the combustion process in order to reach an acceptable life span of the components. As the cooling air is usually extracted from the compressor, the reduction of the cooling effort would directly result to an increased thermal efficiency of the gas turbine. Understanding of the fundamental physics of film cooling is necessary for the improvement of the state-of-the-art. Thus, huge research efforts by industry as well as research organizations have been undertaken to establish high efficient film cooling technologies. It is a today common knowledge that film cooling effectiveness degradation is caused by secondary flows inside the cooling jets, i.e. the Counter-Rotating Vortices (CRV) or sometimes also mentioned as kidney-vortices, which induce a lift-off of the jet. Further understanding of the secondary flow development inside the jet and how this could be influenced, has led to hole configurations, which can induce Anti-Counter-Rotating Vortices (ACRV) in the cooling jets. As a result, the cooling air remains close to the wall and is additionally distributed flatly along the surface. Beside different other technologies, the NEKOMIMI cooling technology is a promising approach to establish the desired ACRV. It consists of a combination of two holes in just one configuration so that the air is distributed mainly on two cooling air streaks following the special shape of the generated geometry. The original configuration was found to be difficult for manufacturing even by advanced manufacturing processes. Thus, the improvement of this configuration has been reached by a set of geometry parameters, which lead to configurations much easier to be manufactured but preserving the principle of the NEKOMIMI technology. Within a numerical parametric study several advanced configurations have been obtained and investigated under ambient air flow conditions similar to conditions for a wind tunnel test rig. By systematic variation of the parameters a further optimization with respect to highest film cooling effectiveness has been performed. A set of most promising configurations has been also investigated experimentally in the test rig. The best configuration outperforms the basic configuration by 17% regarding the overall averaged adiabatic film cooling effectiveness under the experimental conditions.

Double-Jet Ejection of Cooling Air for Improved Film-Cooling

2006 ◽  
Author(s):  
Karsten Kusterer ◽  
Dieter Bohn ◽  
Takao Sugimoto ◽  
Ryozo Tanaka
Keyword(s):  
Film Cooling ◽  
Gas Turbines ◽  
Gas Flow ◽  
Operating Conditions ◽  
Cooling Effectiveness ◽  
Equal Distribution ◽  
Cooling Fluid ◽  
Film Cooling Effectiveness ◽  
Conventional Film ◽  
Cooling Technology

Film-cooling in gas turbines leads to aerodynamic mixing losses and reduced temperatures of the gas flow. Improvements of the gas turbine thermal efficiency can be achieved by reducing the cooling fluid amount and by establishing a more equal distribution of the cooling fluid along the surface. It is well known that vortex systems in the cooling jets are the origin of reduced film-cooling effectiveness. For the streamwise ejection case, kidney-vortices result in a lift-off of the cooling jets; for the lateral ejection case, usually only one dominating vortex remains, leading to hot gas flow underneath the jet from one side. Based on the results of numerical analyses, a new cooling technology has been introduced by the authors, which reaches high film-cooling effectiveness as a result of a well-designed cooling hole arrangement for interaction of two neighbouring cooling jets (Double-jet Film-cooling DJFC). The results show that configurations exist, where an improved film-cooling effectiveness can be reached because an anti-kidney vortex pair is established in the double-jet. The paper aims on following major contributions: • to introduce the Double-jet Film-cooling (DJFC) as an alternative film-cooling technology to conventional film-cooling design. • to explain the major phenomena, which lead to the improvement of the film-cooling effectiveness by application of the DJFC. • to prove basic applicability of the DJFC to a realistic blade cooling configuration and present first test results under machine operating conditions.

The Advanced Cooling Technology for the 1500°C Class Gas Turbines: Steam-Cooled Vanes and Air-Cooled Blades

1997 ◽  
Vol 119 (3) ◽  
pp. 624-632 ◽  
Author(s):  
H. Nomoto ◽  
A. Koga ◽  
S. Ito ◽  
Y. Fukuyama ◽  
F. Otomo ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Electric Power ◽  
Gas Turbine ◽  
Film Cooling ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Cooling Effectiveness ◽  
Impingement Cooling ◽  
Cycle Systems ◽  
Cooling Technology

It is very essential to raise the thermal efficiency of combined cycle plants from the viewpoint of energy saving and environmental protection. Tohoku Electric Power Co., Inc., and Toshiba Corporation in Japan have jointly studied the next generation of combined cycle systems using 1500°C class gas turbine. A promising cooling technology for the vanes using steam was developed. The blades are cooled by air, adopting the impingement cooling, film cooling, and so on. The cooling effectiveness was confirmed both for the vanes and the blades using a hot wind tunnel. This paper describes the design features of the vanes and the blades, and the results of the verification tests using the hot wind tunnel.

Throughflow Method for a Combustion Chamber With Effusion Cooling Modelling

2018 ◽  
Author(s):  
Xiaoheng Liu ◽  
Donghai Jin ◽  
Xingmin Gui
Keyword(s):  
Boundary Condition ◽  
Combustion Chamber ◽  
Film Cooling ◽  
Small Diameter ◽  
Homogeneous Boundary Condition ◽  
Good Prediction ◽  
Combustion Chambers ◽  
Fluent Simulation ◽  
Cylindrical Holes ◽  
Cooling Technology

The most progressive liner cooling technology for modern combustion chambers is represented by effusion cooling (or full-coverage film cooling), which is based on the use of several inclined small diameter cylindrical holes. However, as to simulation of the gas turbine combustion chamber, meshing of these discrete holes needs too much computer resource and demanding calculation time. The homogeneous boundary condition was attempted to apply in the throughflow method for the simulation of the full-scale combustion chamber. The verification of this uniform condition was performed through the model of two straight channels. Obtained results were compared with detailed LES simulations, highlighting well accordance and accurate flow structure around the plate. Furthermore, the modelling was used in the simulation of a loop combustion chamber with throughflow method on isothermal state. Performance characteristic and flow fields from this method were then contrasted with the details from the FLUENT simulation upon high geometric fidelity, and prove that the homogeneous boundary condition exerts a good prediction of the performance characteristics and flow field in the combustion chamber.

Numerical Investigation of Impact of Relative Humidity Condition on Droplet Accumulation and Film Cooling on Compressor Blades

2014 ◽  
Author(s):  
Luz Bugarin ◽  
Antara Badhan ◽  
Shaolin Mao
Keyword(s):  
Heat Transfer ◽  
Relative Humidity ◽  
Gas Turbine ◽  
Power Output ◽  
Film Cooling ◽  
Low Cost ◽  
Continuous Phase ◽  
Droplet Breakup ◽  
Compressor Blades ◽  
The Relationship

In this study, the relationship between the inlet relative humidity (RH) condition, heat transfer, and droplet accumulation/motions on gas turbine’s compressor blades involved in enhanced film cooling was investigated. Wet compression has gained popularity as a highly effective way to increase power output for gas turbine systems due to its simple installation and low cost. This process involves injection of droplets into the continuous phase (air with high temperature) of the compressor to reduce the temperature of the flow leaving the compressor and in turn increase the power output of the whole gas turbine system. This study focused on a single stage rotor-stator compressor model; the simulations are carried out using the commercial CFD tool ANSYS (FLUENT). In particular, the study modeled the interaction between the two phases including mass and heat transfer, given different inlet relative humidity (RH) and temperature conditions. The Reynolds Averaged Navier-Stokes (RANS) equations with k–ϵ turbulence model were applied as well as the droplet coalescence and droplet breakup model considered in the simulation. The interaction between the blade and droplets was modeled to address all possible interactions, which include: stick, spread, splash, or rebound. The goal of this study is to quantify the relationship between the RH and the overall heat transfer coefficient, and the temperature on the blade surface.

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