Table 3 - uploaded by Alok Majumdar
Content may be subject to copyright.
Source publication
The Generalized Fluid System Simulation Program is a finite volume-based, general purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjug...
Context in source publication
Citations
... Generalized Fluid System Simulation Program (GFSSP) [20] is general fluid flow system solver, developed by the National Aeronautics and Space Administration -Marshall Space Flight Centre (NASA-MSFC), which employs finite volume approach to solve the required conservation equations in connection with suitable equation of state. It includes thermodynamic and thermophysical property packages for many fluids. ...
... In addition to directly using the NIST REFPROP program, researchers have also accessed properties from REFPROP indirectly from its inclusion in commercial simulation software such as ANSYS 5 and aspenONE, 6 or by reading input files created from REFPROP as is done by NASA's GFSSP fluid system simulation program. 7 This article summarizes some of the models, features, and limitations of the program. ...
The NIST REFPROP software program is a powerful tool for calculating thermophysical properties of industrially important fluids, and this manuscript describes the models implemented in, and features of, this software. REFPROP implements the most accurate models available for selected pure fluids and their mixtures that are valid over the entire fluid range including gas, liquid, and supercritical states, with the goal of uncertainties approaching the level of the underlying experimental data. The equations of state for thermodynamic properties are primarily of the Helmholtz energy form; a variety of models are implemented for the transport properties. We document the models for the 147 fluids included in the current version. A graphical user interface generates tables and provides extensive plotting capabilities. Properties can also be accessed through third-party apps or user-written code via the core property subroutines compiled into a shared library. REFPROP disseminates international standards in both the natural gas and refrigeration industries, as well as standards for water/steam. © Not subject to U.S.
... The heat transfer coefficient at the fluid-solid interface h I is an important parameter for calculating the heat distribution across the nodes in the lumped node solvers, like GFSSP developed by NASA [39] . h I for the liquid region and vapor region are calculated as, ...
Liquid-vapor phase change models vitally influence the simulation of self-pressurization processes in closed containers. Popular liquid-vapor phase change models, such as the Hertz-Knudsen relation, energy jump model, and their derivations were developed based on room-temperature fluids. Although they had widely been applied in cryogenic simulations with liquid-vapor transitions, the performance of each model was not explicitly investigated and compared yet under cryogenic conditions. A unified multi-phase solver incorporating four typical liquid-vapor phase change models has been proposed in the present study, which enables direct comparison among those models against experimental data. A total number of 171 self-pressurization simulations were conducted to evaluate the evaporation and condensation models’ prediction accuracy and calculation speed. It was found that the pressure prediction highly depended on the model coefficients, whose optimization strategies differed from each other. The energy jump model was found inadequate for cryogenic self-pressurization simulations. According to the average deviation and CPU consumption, the Lee model and the Tanasawa model were proven to be more stable and more efficient than the others.
... Many general-purpose flow prediction programs are available, such as NASA Generalized Fluid System Simulation Program (GFSSP) or EcoSimPro and an adequate heat input model is adopted considering convection, conduction, and radiation. [1][2][3][4] On the other hand, it is also important to provide adequate input heat transfer coefficient that consider actual experimental conditions. Recently, Hartwig and Vera analyzed the transient behavior of the liquid hydrogen line at tens of g/s mass flow rates with GFSSP, 1) but large differences were found between measured and predicted fluid temperatures. ...
... Equations (2) to (4) were used for pressure loss analysis. The pressure loss of the bend or tee was calculated by giving the equivalent length ⁄ in Eq. (2). As for the friction factor appearing in Eq. (2), both the Blasius's equation (Eq. ...
A precise prediction of the cryogenic fluid system is not an easy task especially at relatively smaller mass flow rates, because the heat input to the working fluid from the surroundings becomes significant. We conducted a series of flow tests with liquid oxygen to measure temperature, density, and the pressure loss characteristics at a flow rate of 100-200 g/s, and we compared them to the prediction. The heat input to the working fluid obtained from the experiment was about 14-18 kJ/kg. Also, the heat transfer coefficient through the insulated tube wall was calculated from the experiment. The temperature rise along the feedline was well explained with K = 0.28-0.79 W/m-K whereas the theoretical model gives K = 0.044 W/m-K.
... Associate Professor, Computer Science Department. 2 Aerospace Technologist, Propulsion Systems Department, AIAA Senior Member. 3 Aerospace Technologist, Propulsion Systems Department. ...
... Verma [2]presented the algorithm for steam transport in a geothermal pipeline, considering the conservation of mass and momentum (Newton's second law) and the first and second laws of thermodynamics [14,15]. In the pipeline network of the geothermal power plant, the steam flows from high to low pressure and heat flows from high to low temperature (i.e., indirectly validation of second law of thermodynamics). ...
In the project CEMIE-Geo, the development of a steam transport simulator, GeoSteam.Net for a geothermal pipeline network is in progress. The steam-transportation algorithm considers the conservation of mass, linear momentum, and total (mechanical plus thermal) energy. The simulator is useful for the optimization of(i) design and contraction, (ii) monitoring and operation and (iii) decision making in the update and modification of the geothermal power plant. A demo program, DemoGeoSteam.Net for the solution of the well-known problem of three reservoirs (i.e. three pipes that connect two production wells and one power plant) is written in C# on the Windows platform, which can be downloaded from the website http://www.INEELGeoSteam.Net/WtrStmTbl. Similarly, an illustration is presented in defining the pipeline diameters of the above three reservoirs geothermal pipeline network.
... Finite Volume Method (FVM) is used to establish different conservation equations. 23 This software is still developing in recent years by adding new models and improving algorithm, and the current version is GFSSP Version 701 released in Dec. 2015. REDS (Rocket Engine Dynamic Simulator) 28 has been developed by JAXA (Japan Aerospace Exploration Agency) in Japan since 2001. ...
For a typical pressurized system with a novel dual-stage gas pressure reducing regulator, a system model is established with modular models of various typical components. The simulation study on the whole working period shows that the general trends and magnitudes of simulation curves are in agreement with experimental measured curves. As the key component in the pressurized system, the regulator is studied by a series of numerical simulations to reveal the influences of various structure parameters on its stability. Furthermore, the variable ranges which can guarantee the stability of regulator and system are obtained to provide guidance for design. The modeling and analysis approach can be applied to other systems and components.
... The self-pressurization model used in this work was based on NASA's GFSSP Example 29 "Self-Pressurization of a Cryogenic Propellant Tank Due to Boil-off" [2] pressurization of a ground-based liquid hydrogen tank that was conducted under the Multi-Purpose Hydrogen Test Bed (MHTB) program. The original problem investigates a Thermodynamic Vent System (TVS). ...
... Only the self-pressurization portion of the tank model was investigated to determine the effects of dissolved helium on the tank performance. A detailed discussion of the tank and the thermodynamic relations used to solve the system can be found in the GFSSP Supplemental Materials for version 701 [2]. A brief overview of the tank and thermodynamic relations used is presented. ...
A model was developed using NASA's Generalized Fluid System Simulation Program (GFSSP) for the self-pressurization of a liquid hydrogen propellant tank due to boil-off to determine the significance of mixture non-idealities. The GFSSP model compared the tank performance for the traditional model that assumes no helium pressurant dissolves into the liquid hydrogen propellant to an updated model that accounts for dissolved helium pressurant. Traditional NASA models have been unable to account for this dissolved helium due to a lack of fundamental property information. Recent measurements of parahydrogen-helium mixtures enabled the development of the first multi-phase Equation Of State (EOS) for parahydrogen-helium mixtures. The self-pressurization GFSSP model was run assuming that the liquid propellant was pure liquid hydrogen and assuming helium dissolved into the liquid utilizing the new helium-hydrogen EOS. The analysis shows that having dissolved helium in the propellant does not have a significant effect on the tank pressurization rate for typical tank conditions (-423 °F and 30 psia).
... It can be seen by comparison and analysis: 1) The biggest problem in the basic theory of all kinds of system-level models, in many cases [19][20][21][22]41,42], is that there is lack of a unified and comprehensive basic equation set in integral or differential form which can cover basic phenomena such as flow, heat transfer and combustion as well as its derivation process; 2) Since the method of characteristics (MOC) [43] is not suitable to deal with complicated component boundary connection relationship and has congenital deficiency in multi-component modularization modeling, and the finite difference method (FDM) [43] has difficulty to ensure the scheme conservation, the staggered-grid finite volume method (FVM) [43,44] will gradually replace MOC and FDM and become the mainstream discretization method for establishing large numerical simulation systems; 3) For the modularization algorithm of a specific component, basic simulation theory has fundamentally determined component algorithm's precision and detail level on which the physical phenomena can be described. And how to derive the specific modularization algorithm from the basic simulation theory according to the specific structure of a component decides the specific form of the component algorithm. ...
Due to the lack of a theoretical basis for multi-field coupling in many system-level models, a novel set of system-level basic equations for flow/heat transfer/combustion coupling is put forward. Then a finite volume model of quasi-1D transient flow field for multi-species compressible variable-cross-section pipe flow is established by discretising the basic equations on spatially staggered grids. Combining with the 2D axisymmetric model for pipe-wall temperature field and specific chemical reaction mechanisms, a finite volume model system is established; a set of specific calculation methods suitable for multi-field coupling system-level research is structured for various parameters in this model; specific modularisation simulation models can be further derived in accordance with specific structures of various typical components in a liquid propulsion system. This novel system can also be used to derive two sub-systems: a flow/heat transfer two-field coupling pipe-flow model system without chemical reaction and species diffusion; and a chemical equilibrium thermodynamic calculation-based multi-field coupling system. The applicability and accuracy of two sub-systems have been verified through a series of dynamic modelling and simulations in earlier studies. The validity of this system is verified in an air–hydrogen combustion sample system. The basic equations and the model system provide a unified universal theory and numerical system for modelling and simulation and even virtual testing of various pipeline systems.
... .) qui sont eux-mêmes décrits de façon simplifiée, souvent en 1D ou en quasi-1D. Les lois de conservation régissant l'écoulement de fluide dans ces composants sont discrétisées par une approche de type volumes finis [51]. Cette formulation permet de connaître la température et la pression dans les différentes parties du système (notamment phases liquide et vapeur ainsi que parois du réservoir) pour un coût de calcul raisonnable (par rapport à une approche CFD multidimensionnelle classique) qui autorise la simulation efficace de plusieurs phases de contrôle. ...
Future operations in space exploration require the ability to store cryogens for long duration. Residual heat loads induce cryogenic propellant vaporization and tank self-pressurization (SP), eventually leading to storage failure for long enough mission duration. This thesis focuses on a control strategy, called Thermodynamic Venting System (TVS), based on a recirculating liquid subcooled injection. The injection results in an ullage condensation, a liquid bath destratification and thus a tank pressure reduction. Experimentally, an original active insulation technique has been set up, yielding a net zero heat flux wall boundary condition. A data base of self-pressurisation and TVS control experiments has been gathered with this new aparatus. It was used to validate an homogeneous thermodynamic model providing a fast prediction of tank temperature and pressure during control. This model has been extended to discribe the TVS system behaviour including all its components. This full system design tool has been coupled with an optimisation platform and an optimal TVS design has been established for a demonstration mission. Furthermore, a numerical study has evidenced the weakness of commercial CFD software to simulate phase change, for TVS configuration. A predictive phase change formulation has been set up in a home-made software and validated on a 1D academic case.
