Experimental and numerical results from the world's first advanced adiabatic compressed air energy storage (AA-CAES) pilot-scale plant are presented. The was built in an unused tunnel with a diameter of 4.9 m which two concrete plugs delimited mostly unlined cavern 120 length. sensible thermal-energy (TES) capacity 12 MWhth placed inside cavern. pilot operated charging/discharging cycles various durations, temperatures up to 550 °C, maximum gauge pressures 7 bar. Higher could not be reached...

Six types of rocks Alpine origin were investigated for their suitability high-temperature packed-bed thermal-energy storage. The thermally cycled in laboratory furnaces between about 100 °C and 600°C with a heating rate 2.6°C/min assessed terms specific heat capacity porosity as well the degree cracking, fracturing, disintegration. Thermal cycling was found to lead decreases increases rocks. These changes are explained by physical chemical reactions such mineral dehydration,...

We review the literature on analytical models of advanced adiabatic compressed air energy storage plants with isochoric reservoirs, a focus insights that can be extracted from models.The indicates for turbomachinery, and without throttling is missing literature.We proceed to derive such models, assuming plant operating at quasi-steady state, treated as calorically thermally perfect gas, thermal-energy units are free thermal pressure losses.The result in closed-form expressions key...

The discretization of Navier-Stokes equations on mixed unstructured grids is discussed. Because consist different cell types, the question arises as to how should treat these types in order result a stable and accurate solution method. This issue addressed relation inviscid viscous fluxes. fluxes carried out with both centered an upwind scheme. For scheme, problems exist damping properties fourth-difference operator. operator are investigated for two stencils by truncation error Fourier...

Viscous compressible flow around a sphere is considered in the limit of zero Reynolds and Mach numbers. An exact expression for force on undergoing arbitrary motion with compressibility effects presented. Quasisteady, inviscid-unsteady, viscous-unsteady components are identified. Numerical results excellent agreement theory. The present formulation offers an explicit unsteady time domain can be as generalization Basset-Boussinesq-Oseen equation to flow.

MPIRICALcorrelationsforthequasi-steadydragcoef!cientofa sphere in compressible ow have been presented by severalauthors (e.g., Henderson [1] and Loth [2]). Such correlations areneeded numerical simulations of multiphase owsinvolving spherical particles. In this Note, the accuracy thecorrelationsofHenderson[1]andLoth[2]areassessedusingthedatacollectedbyBaileyandStarr[3],andanimprovedcorrelationforthedrag coef!cient a is developed. Theimproved correlation validated for shock-particle...

Abstract Linearized viscous compressible Navier–Stokes equations are solved for the transient force on a spherical particle undergoing unsteady motion in an inhomogeneous ambient flow. The problem is formulated reference frame attached to and contributions from undisturbed flow perturbation separated. Using density-weighted velocity transformation reciprocal relation, total first obtained Laplace domain then transformed time domain. separated into quasi-steady, inviscid unsteady,...

Experimental and numerical results from the world's first pilot-scale advanced adiabatic compressed air energy storage plant with combined sensible/latent thermal-energy are presented. The was composed of sensible latent units maximum capacities 11.6 MWhth 171.5 kWhth, respectively. consisted a steel tank 296 stainless-steel tubes encapsulating an Al–Cu–Si alloy as phase-change material. investigated using four charging/discharging cycles durations about 3 h each inflow temperatures up to...

This work presents a framework for comparing reactor concepts thermochemical storage and analyzing their impact on the performance of CSP plants.

A solution method for compressible turbulent flows on unstructured grids in two dimensions is described. The can be used consisting of triangular and/or quadrilateral cells. Control volumes are constructed from dual cells, and the variables stored at vertices grid. Grid-transparent algorithms developed that do not require knowledge cell types, leading to simple discretization schemes mixed grids. inviscid fluxes computed limited high-resolution originally They easily applied or grid...

Abstract A new procedure for modeling the conjugate heat‐transfer process between fluid and structure subdomains is presented. The relies on higher‐order combined interface boundary conditions (CIBC) improved accuracy stability. Traditionally, continuity of temperature heat flux along interfaces satisfied through algebraic jump in a staggered fashion. More specifically, Dirichlet are usually imposed side Neumann heat‐flux solid stability conventional sequential procedure. In this type...

A constrained multi-objective optimization approach is applied to optimize the exergy efficiency and material costs of thermocline packed-bed thermal-energy storage systems using air as heat-transfer fluid. The axisymmetric packed-bed's height, top bottom radii, insulation-layer thicknesses, particle diameter were chosen design variables. competing objectives maximizing minimizing treated by a Pareto front. front allows identifying most efficient for given cost or cheapest an important tool...

Covers advancements in spacecraft and tactical strategic missile systems, including subsystem design application, mission analysis, materials structures, developments space sciences, processing manufacturing, operations, applications of technologies to other fields.

The unsteady inviscid force on cylinders and spheres in subcritical compressible flow is investigated. In the limit of incompressible flow, a cylinder or sphere so-called added-mass that proportional to product mass displaced by body instantaneous acceleration. finite acoustic propagation speed means arising from an instantaneously applied constant acceleration develops gradually reaches steady values only for non-dimensional times c ∞ t / R ≳10, where freestream sound radius sphere. this...

Thermocline thermal-energy storage (TES) suffers from so-called thermocline degradation, which refers to the flattening of temperature gradients in TES with successive charging-discharging cycles. degradation increases variations heat-transfer fluid (HTF) outflow temperatures, decreases utilization factors, and specific material costs. Methods that prevent or reduce by changing operation are called thermocline-control (TCC) methods. The assessment TCC methods is main objective this work....

The interaction of shock waves with deformable particles is an important fundamental problem. In some applications, e.g., the detonation explosives loaded metal particles, pressure behind wave can be significantly larger than yield strength particle material. This means that deform severely during their wave. experimental and theoretical studies (SIDP) are extremely challenging because its highly transient nature. As a result, no accurate model exists yet used in simulations. objective this...