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At low advance ratios that are much smaller than the advance ratio where the maximum efficiency of the propeller is obtained, large portions of the blades' cross-sections operate at stall conditions. Using two-dimensional non-rotating airfoil data to calculate the propeller's aerodynamic performance at low advance ratios, results in large differenc...
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Citations
... Compressibility and viscous effects are simulated with XFOIL. Different momentum equation models are realised for simulation of static, high-speed, and recuperation operation, e.g., [59,65]. The baseline in this publication for the comparison with the other tools is a linear momentum theory. ...
This paper compares several blade element theory (BET) method-based propeller simulation tools, including an evaluation against static propeller ground tests and high-fidelity Reynolds-Average Navier Stokes (RANS) simulations. Two proprietary propeller geometries for paraglider applications are analysed in static and flight conditions. The RANS simulations are validated with the static test data and used as a reference for comparing the BET in flight conditions. The comparison includes the analysis of varying 2D aerodynamic airfoil parameters and different induced velocity calculation methods. The evaluation of the BET propeller simulation tools shows the strength of the BET tools compared to RANS simulations. The RANS simulations underpredict static experimental data within 10% relative error, while appropriate BET tools overpredict the RANS results by 15–20% relative error. A variation in 2D aerodynamic data depicts the need for highly accurate 2D data for accurate BET results. The nonlinear BET coupled with XFOIL for the 2D aerodynamic data matches best with RANS in static operation and flight conditions. The novel BET tool PropCODE combines both approaches and offers further correction models for highly accurate static and flight condition results.
... Different momentum equation models are realised for the simulation of static condition, high-speed conditions and recuperation, e.g. [20,49]. For this publication a linear momentum theory approach is selected in combination with the Prandtl tip loss correction procedure, without any post-stall model and sweep correction model. ...
In this paper, common open-source simulation propeller tools are compared and evaluated against high fidelity RANS simulations and static propeller ground tests. Comparison of moving reference frame and rigid body motion RANS simulations and blade element method simulations provide statements about the accuracy of the different low fidelity simulation tools. Not only accuracy but although computational effort and ease of handling of the tools are assessed. The evaluation is performed with proprietory propeller geometry and simulation data is compared against static test stand data. The evaluation shows the advantages and disadvantages, as well as the capabilities of the different propeller simulation tools. The paper quantifies the errors and applicability of blade element methods in static conditions as well as in flight conditions. Compared to static test bench results, 10 to 15% relative errors must be expected when using suitable blade element methods. Basic linear momentum theory approaches coupled with simple Prandtl Tip loss correction methods are sufficient for propeller performance predictions in early design stages.
