If automatic time incrementation is not selected in the analysis procedure, values of PNEWDT that are greater than 1.0 will be ignored and values of PNEWDT that are less than 1.0 will cause the job to terminate. # ENER Energy per unit mass stored in the fluid. This variable is used for energy output only and has no effect on the solution. # Variables passed in for information # PRESS Fluid cavity pressure at the end of the increment. For a linear perturbation step this is the base state pressure. # DPRESS Fluid cavity pressure increment. For a linear perturbation step this value is zero. # PRESSI Fluid cavity pressure at the beginning of the analysis. # TEMP Fluid cavity temperature at the end of the increment. For a linear perturbation step this is the base state temperature. # DTEMP Fluid cavity temperature increment. For a linear perturbation step this value is zero. # TEMPI Fluid cavity temperature at the beginning of the analysis. # TIME(1) Current value of step time at the start of the increment. # TIME(2) Current value of total time at the start of the increment. # DTIME Time increment. # KSTEP Step number. # KINC Increment number. # NONUM Cavity reference node number. # FLNAME User-specified fluid property name, left justified. # LFLAG Linear perturbation flag for the step. If this is a linear perturbation step, LFLAG=1. For a general analysis step LFLAG=0. # 1.1.34 UFLUIDCONNECTORLOSS: User subroutine to define the loss coefficient for fluid flow in fluid pipe connector elements. Product: Abaqus/Standard # Reference • \*FLUID PIPE CONNECTOR LOSS # Overview User subroutine UFLUIDCONNECTORLOSS: • can be used to define the loss coefficient in a fluid pipe connector element; • corresponds to the Darcy-Weisbach equation for pressure loss; and • can be used with the fluid pipe connector elements. # User subroutine interface ```txt subroutine ufluidconnectorloss ( C Write only - * ak1, ak2, C Read only - * coords, flow, rho, visc, * dia, area, * ndim, jelno, kStep, kInc, * time, * nIarray, * i_array, * nRarray, * r_array, * ncarray, * c_array) C include 'aba_param.inc' C dimension time(2), * coords(2*ndim), * i_array(nIarray), * r_array(nRarray) C character*80 c_array(ncarray) ``` C ```lua user coding to define connector friction values return end ``` # Variables to be defined ak1 This connector loss coefficient must be updated and is used when the flow is from node 1 to node 2. ak2 This connector loss coefficient must be updated and is used when the flow is from node 2 to node 1. # Variables passed in for information coords(2\*ndim) Array containing original coordinates of the element. coords(1:ndim) is the coordinate of the first node, and coords(ndim+1:2\*ndim) is the coordinate of the second node. flow Current flow rate through the element. rho Current density of fluid flowing through the pipe. visc Current viscosity of fluid flowing through the pipe. dia User-specified hydraulic diameter. area User-specified hydraulic area. ndim Dimension of the element. jelno User element number for which friction coefficient is required. kStep Step number. kInc Increment number. time(1) Current step time. time(2) Total time. nIarray Size of array i\_array. i\_array Integer array for future expansion. nRarray Size of array r\_array. r\_array Real array for future expansion. ncarray Size of array c\_array. c\_array Character array for future expansion. # 1.1.35 UFLUIDCONNECTORVALVE: User subroutine to define the valve opening to control flow in fluid pipe connector elements. Product: Abaqus/Standard # Reference • \*FLUID PIPE CONNECTOR LOSS # Overview User subroutine UFLUIDCONNECTORVALVE: • can be used to control the valve opening to turn off or turn on fluid flow; and • can be used with fluid pipe connector elements. # User subroutine interface ```txt subroutine ufluidconnectorvalve ( C Write only - * valveOpening, C Read only - * coords, flow, rho, visc, * dia, area, * ndim, jelno, kStep, kInc, * time, * nIarray, * i_array, * nRarray, * r_array, * ncarray, * c_array) C include 'aba_param.inc' C dimension time(2), * coords(2*ndim), * i_array(nIarray), * r_array(nRarray) C character*80 c_array(ncarray) C ``` ```lua user coding to define control valve opening return end ``` # Variable to be defined valveOpening The value of this variable must be set between 0.0 (closed/shut-off) and 1.0 (fully open) to determine whether the valve is fully or partially open or closed. # Variables passed in for information coords(2\*ndim) Array containing the original coordinates of the element. acoords(1:ndim) is the coordinate of the first node, and acoords(ndim+1:2\*ndim) is the coordinate of the second node. flow Current flow rate through the element. rho Current density of fluid flowing through the pipe. visc Current viscosity of fluid flowing through the pipe. dia User-specified hydraulic diameter. area User-specified hydraulic area. ndim Dimension of the element. jelno User element number for which a friction coefficient is required. kStep Step number. kInc Increment number. time(1) Current step time. time(2) Total time. nIarray Size of array i\_array. i\_array Integer array for future expansion. nRarray Size of array r\_array. r\_array Real array for future expansion. ncarray Size of array c\_array. c\_array Character array for future expansion.