Wind Tunnel Performance of Four Energy Efficient Propellers Designed for Mach 0.8 Cruise

Jeracki, Robert J.; Mikkelson, D. C.; Blaha, B. J.

doi:10.4271/790573

Cited by 27 publications

(9 citation statements)

References 10 publications

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“…6, which also extends the validation to higher Mach numbers and compares against the ideal and measured real efficiencies quoted by Jeracki et al [39], for the design point advance ratio and power coefficient of the SR3 propeller. The ideal efficiency is the efficiency of the propeller for zero profile drag conditions, whereas the no-induced efficiency is the efficiency with all the induced velocities set to zero (i.e., only the viscous drag losses are taken into account).…”

Section: Methods Invalid Outside Available Propeller Spectrumsupporting

confidence: 71%

Toward a Scalable Propeller Performance Map

Giannakakis

Laskaridis

Nikolaidis

et al. 2015

Journal of Propulsion and Power

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Propeller performance is traditionally represented by a performance map that gives propeller efficiency as a function of the flight Mach number, the power coefficient C P , and the advance ratio J. This work aims to demonstrate how this map changes when the design C P and J change and to propose a novel map format that is able to capture the performance of different propeller designs. For this purpose, the propeller performance is simulated using a propeller lifting-line method validated for the SR3 propfan. Subsequently, the propeller model is used within a sequential quadratic programming framework to optimize the blade twist and chord distribution for different sets of design C P and J. A complete propeller performance map is then generated for each one of the optimized designs. The results demonstrate that all the investigated propellers can be modeled by a common map, which determines separately the ideal efficiency and the viscous losses. The ideal efficiency is given in the traditional format of η i fC P ;J, whereas the viscous losses are represented as a function of the relative variables C P ∕C Pdes and J∕J des .

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Section: Methods Invalid Outside Available Propeller Spectrumsupporting

confidence: 71%

Toward a Scalable Propeller Performance Map

Giannakakis

Laskaridis

Nikolaidis

et al. 2015

Journal of Propulsion and Power

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“…This effect is not seen in the predicted results. The effect 3 arises from the tip vortex rollup which is not included in the analysis.…”

Section: Resultsmentioning

confidence: 99%

“…A recent study (3) has shown that this propeller has both good noise characteristics and high aerodynamic efficiencies. The ~R-3 propeller has been studied using a laser velocl·m~ter (LV) to determine the flow field 4).…”

Section: Introductionmentioning

confidence: 99%

An analytical and experimental comparison of the flow field of an advanced swept turboprop

Neumann

Bober²,

Serafini³

et al. 1983

21st Aerospace Sciences Meeting

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An argon ion laser velocimeter (LV) with four beams has been used to measure the detailed flowfield of an advanced eight blade propeller with 4S· of tip sweep in the Lewis 8x6 Foot Supersonic Wind Tunnel. The propeller was tested at a Mach number of 0.8. The propeller operated at an advance ratio of 3.06 and a blade angle at the three-fourths radius of 60.5·. The test configuration was also analyzed using a curved lifting line analysis. A comparison of analysis results with LV data indicated blade blockage occurred near the nacelle. This resulted in a deceleration ahead of the blade and unsteady flow downstream. The LV data also indicated the presence of a shock wave emanating from the suction surface at a radius ratio of 0.79. The curved lifting line analysis qualitatively predicted the SR-3 propeller flow field. The comparison showed some differences between prediction and LV measurements. These aifferences can be attributed to phenomena not included in tne analysis such as viscous blade wakes, tip vortex rollup, blade blockage, and nacelle effects. Tne comparison has indicated underpredictions in the magnitude of the radial velocity jump across the blade. These differences lead to differences in blade loading and wake location. advance ratio, Vo/nD Mach number rotational speed, revolutions per second power, kW (ft-lb/sec) radius, cm (in.) blade tip radius, cm (in.) free-stream velOCity, m/sec (ft/sec) tip rotational velocity, m/sec (ft/sec) axial distance from nose of spinner, cm (in. ) ratio of total temperature to standard sea-level temperature of 518.7· R free-stream density, kg/m 3 (slugs/ft 3 )

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“…NASA made a series of designs and suggested tests for implementing aerodynamic sweep. 2,3,4,5,6 Significant improvements in efficiency and noise reduction were achieved at high subsonic Mach numbers (0.7-0.8). 6 NASA's work at that time focused primarily on single rotation propellers by using an axial backward aerodynamic sweep similar to that researched in the 1940-50's.…”

Section: Introductionmentioning

confidence: 99%

“…6 NASA's work at that time focused primarily on single rotation propellers by using an axial backward aerodynamic sweep similar to that researched in the 1940-50's. 1,2,3,4,5,6 To further explore the theoretically higher efficiency of a turboprop when compared to a turbofan, counter-rotating propeller concepts were proposed to reduce the swirl loss induced by a single propeller blade. 6 General Electric conducted a design of counterrotating propellers as a contract from NASA in 1994.…”

Section: Introductionmentioning

confidence: 99%

High Efficiency Forward Swept Propellers at Low Speeds

Paxton

Gryn

Hines

et al. 2003

41st Aerospace Sciences Meeting and Exhibit

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Propellers with forward sweep were studied in order to determine whether this type of sweep produces a more efficient propulsion source. The sweep effect is achieved solely by tangentially leaning the leading edge of the blades toward the direction of rotation. Eight 155mm (6.1") diameter propeller designs were created for testing; one straight blade, used for comparison, and seven swept blades using different sweep angles and configurations. Wind tunnel tests were conducted on all blades and CFD simulations were made for the straight blade as well as the best performing swept designs from the wind tunnel results. While efficiency values from wind tunnel tests and CFD simulations were not the same, the trends created in both were considered to be comparable. The general trend established shows that the swept blades not only have higher efficiencies but also have greater stall margins. Some speculated reasons for these advantages are given.

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Wind Tunnel Performance of Four Energy Efficient Propellers Designed for Mach 0.8 Cruise

Cited by 27 publications

References 10 publications

Toward a Scalable Propeller Performance Map

Toward a Scalable Propeller Performance Map

An analytical and experimental comparison of the flow field of an advanced swept turboprop

High Efficiency Forward Swept Propellers at Low Speeds

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