Ceramics for Abradable Shroud Seal Applications

Contribution in Optimization of Honeycomb Abradable Seals Structure

“…This could play a significant role to decrease in the micro-rupture force due to pulling particles out of the coating layer and therefore increasing the effect of seal' abradability. The honeycomb structure also provides the mechanical anchoring for a coating layer where the cell acts as a strain isolator -this a unique feature to facilitate a thermalshock resistance of the applied coating [8]. The shading effects from the thermal spray mass flux resulting from gas vortices generation were also observed to play a critical role in developing coating layer defects near the rib (Figure 3a), suggesting optimization in honeycomb cell design.…”

“…Air Plasma abradable coating offers extended temperature operating capability and greater spray process control to achieve the required coating morphology. Sporer et al proposed an alternative approach of coating abradable materials in the structured surface to meet cyclic thermal resistance [8]. The thermally sprayed abradable ceramics on the structured surface have advantages of dense coating thickness to rub inclusion, better coating adhesion, and thermal shock resistance.…”

Studying and designing improved coatings for labyrinth seals of gas­turbine engine turbines

“…10. Seal of the GTE turbine, the TV3-117 family: nominal (a); worn out (b); KNA sealing coating (1); turbine rotor ridges (2) The change of the flow regime from laminar to turbulent one results in a sharp growth of wave resistance and as a consequence, a fall of air flow rate. At the same time, maintaining of the nominal clearance and the ridge geometry are the most important factors determining operation efficiency.…”

“…Improvement of operation effectiveness of present-day aircraft gas turbine engines (GTE) is one of important tasks of aircraft engine building [1,2]. Gas turbine engine efficiency coefficient (EC) is improved by a number of measures.…”

Thermal Spraying, Optimization And Characterization Of Abradable Seal Coating For Gas Turbine For Service Temperature Up To 750° C

“…1. Figure 1.Cross section of high pressure stage of a gas turbine engine [1]. η = η ref (1) where k = 1+ 0.586 ( ψ ztip 3.63 ) η is the rotor efficiency with tip clearance effects included δ is the tip clearance height h is the blade span ψ ztip is the tip Zweifel loading coefficient It is estimated that an increase in efficiency by 0.5% for a 1000MW plant would save 1 Million dollars per year, along with the reduction in the emission of CO 2 [3].…”