Complex vortical secondary flows that are present near the endwall of an axial gas turbine blade responsible for high heat transfer rates and aerodynamic losses. The application nonaxisymmetric, three-dimensional contouring to surface has been shown reduce strength decrease total pressure losses when compared with a flat endwall. reduction in flow nonaxisymmetric might also be expected transfer. In this study, measurements were taken low-pressure geometry both contoured endwalls. Endwall oil...

Three-dimensional contouring of the compressor and turbine endwalls in a gas engine has been shown to be an effective method reducing aerodynamic losses by mitigating strength complex vortical structures generated at endwall. Reductions endwall heat transfer have also previously measured reported literature. In this study, computational fluid dynamics simulations blade with without nonaxisymmetric were compared experimental measurements exit flowfield, transfer, film-cooling. Secondary...

Shaped film cooling holes are used as a technology in gas turbines to reduce metal temperatures and improve durability, they generally consist of small metering section connected diffuser that expands one or more directions. The area ratio (AR) these is defined the at exit diffuser, divided by section. A larger AR increases diffusion coolant momentum, leading lower average momentum jet hole better performance. Cooling with ARs also tolerant high blowing conditions, increased typically...

Shaped film cooling holes are a well-established technique used in gas turbines to keep component metal temperatures an acceptable range. One of the goals is reduce driving temperature for convection at wall, success which generally represented by adiabatic effectiveness. However, introduction jet-in-crossflow, especially if it oriented compound angle, can augment convective heat transfer coefficient and dominate flowfield. This work aims understand effect that angle has on flowfield...

To enable turbine components to withstand high combustion temperatures, they are cooled by air routed from the compressor, which can leak through gaps between components. These vary in size thermal expansions that take place. The leakage flow interface of combustor and turbine, particular, interacts with flowfield along endwall. This study presents measurements adiabatic cooling effectiveness heat transfer coefficients on endwall a first vane, presence flush slot upstream vane. effect axial...

Turbine vanes are generally manufactured as single- or double-airfoil sections that assembled into a full turbine disk. The gaps between the individual sections, well gap disk and combustor upstream, provide leakage paths for relatively higher-pressure coolant flows. This is intended to prevent ingestion of hot combustion flow in primary gas path. At vane endwall, this can interfere with complex vortical present there thus affect heat transfer surface. To determine effect through gaps,...

One significant hurdle in additively manufacturing polymer-derived ceramics lies reconciling the lower mechanical properties of manufactured parts compared to traditionally and PDCs. Here, a methodology is presented for evaluating influence layer thickness exposure on within constraints commercially available software hardware. Maximizing printable limitation DLP processes, produced green bodies with highest conversion, resulted improved pyrolysis outcomes, manufacturability, most...

Abstract Entry region heat transfer is known to provide significantly higher than fully developed conditions. Utilizing entry would an additional sink at the inlet of aircraft engine before fan, but requires further investigation convective augmentation and downstream boundary layer impacts. The addition near wall features only in high Reynolds numbers uncommon. Thus, enhancement comparing small entrance a circular channel effect on has not been investigated. This study investigates three...

To enable turbine components to withstand high combustion temperatures, they are cooled by air routed from the compressor, which can leak through gaps between components. These vary in size thermal expansions that take place. The leakage flow interface of combustor and turbine, particular, interacts with flowfield along endwall. This study presents measurements adiabatic cooling effectiveness heat transfer coefficients on endwall a first vane, presence flush slot upstream vane. effect axial...

Turbine blade components in an engine are typically designed with gaps between parts due to manufacturing, assembly, and operational considerations. Coolant is provided these limit the ingestion of hot combustion gases. The interaction gaps, their leakage flows, complex vortical flow at endwall a turbine can significantly impact heat transfer coefficients effectiveness providing localized cooling. In particular, platform gap through passage, representing mating interface adjacent blades...

Designing turbine components for maximum aerodynamic performance with adequate cooling is a critical challenge gas engineers, particularly at the endwall of turbine, due to complex secondary flows. To complicate matters, impurities from fuel and intake air can deposit on film-cooled downstream combustor. Deposition-induced roughness reduce effectiveness dramatically. One method commonly used reducing effects flows contouring. The current study evaluates deposition contouring given change...

Shaped film cooling holes are used extensively in gas turbines to reduce component temperatures. These generally consist of a metering section through the material and diffuser spread coolant over surface. two hole features created separately using electrical discharge machining (EDM), occasionally, an offset can occur between meter due misalignment. The current study examines potential impact this manufacturing defect effectiveness for well-characterized shaped known as 7-7-7 hole. Five...

The boundary layer on the endwall of an axial turbomachine passage is influenced by streamwise and cross-stream pressure gradients, as well a large vortex, that develop in passage. These influences distort structure result heat transfer friction coefficients differ significantly from simple two-dimensional layers. Three-dimensional contouring has been shown to reduce strength vortex transfer, but mechanisms reductions are not understood. This study describes three-component measurements mean...

Turbine blade components in an engine are typically designed with gaps between parts due to manufacturing, assembly, and operational considerations. Coolant is provided these limit the ingestion of hot combustion gases. The interaction gaps, their leakage flows, complex vortical flow at endwall a turbine can significantly impact heat transfer coefficients effectiveness providing localized cooling. In particular, platform gap through passage, representing mating interface adjacent blades...

Shaped film cooling holes are a well-established technique used in gas turbines to keep component metal temperatures an acceptable range. One of the goals is reduce driving temperature for convection at wall, success which generally represented by adiabatic effectiveness. However, introduction jet-in-crossflow, especially if it oriented compound angle, can augment convective heat transfer coefficient and dominate flowfield. The present work aims understand effect that angle has on flowfield...

Abstract Additive manufacturing (AM) enables improved heat exchanger (HX) designs where performance is based on the achievable geometry. However, consequences of AM process that affect HX such as increased surface roughness, dimensional tolerance issues, and defects like cracks may vary among identically designed parts due to machine settings. This paper experimentally compares thermal hydraulic three HXs built using a traditionally manufactured, stamped aluminum oil cooler design. The...

Abstract Ceramic matrix composite (CMC) parts create the opportunity for increased turbine entry temperatures within gas turbines. To achieve highest possible, film cooling will play an important role in allowing to exceed acceptable surface CMC components, just as it does current generation of components. Film over a introduces new challenges including roughness features downstream holes and changes hole exit due uneven topography. better understand these impacts, this study presents...