|
|
|
Foundation ::
Engineering Applications ::
PUMPA
|
PUMPA
Centrifugal and Axial Pump Design and Off-design Meanline Performance
|
 |
|
SOURCE CODE AVAILABLE
|
|
PUMPA is a meanline pump-flow modeling method for rapid modelling of cryogenic rocket engine pumps. The program predicts the performance of pumps at off-design operating conditions, given the loss of the diffusion system at the design point. The design-point rotor efficiency and slip factor are obtained from empirical correlations to rotor-specific speed and geometry. The PUMPA code can model axial, inducer, mixed-flow, and centrifugal pumps and can model multistage pumps in series. PUMPA is an effective analysis and conceptual design tool featuring rapid input setup and computer run time, map-generation capabilities that provide the information needed for interfacing with a rocket engine system modeling code, and off-design and multistage modeling capabilities that permit parametric design space exploration of candidate pump configurations and provide headflow maps for engine system evaluation.
PUMPA is based on the Euler equation coupled with empirical correlations for rotor efficiency. The code provides an estimate of flow incidences, losses, and cavitation inception at off-design operating conditions. Both the rotor efficiency and the slip factor can be modified to match test data by means of correction factors. For a given set of pump inlet pressure and temperature, PUMPA can generate a performance characteristic map. The fluids that may be used in PUMPA models are liquid hydrogen, liquid oxygen, liquid nitrogen, JP-4, water, and air. Fluid properties are obtained from GASPLUS. A version of GASPLUS that is designed to work with PUMPA is included in the PUMPA package.
PUMPA output consists of flow conditions at the rotor leading and trailing edges, as well as the diffusion system inlet, throat, and outlet. In addition to the meanline flow conditions at the root-mean-square radius of the rotor, conditions at the hub and tip locations are also calculated. The output describes the flow conditions in terms of velocities, flow angles, pressures, and temperatures. Velocities and flow angles are calculated in both the relative and the absolute frames of reference. Static and total pressures and temperatures are calculated at the discharge of the rotor and stage. The total head rise, horsepower, and efficiency are summarized for each stage and for the overall pump. The calculation of all performance parameters is repeated at every point of an array of off-design conditions.
PUMPA carries the NASA case number LEW-16173. It was originally released as part of the NASA COSMIC collection.
|
|
More software from National Technology Transfer Center
|
|
|
|
|
|
