Super Angebote für Flow Five 2019 hier im Preisvergleich. Große Auswahl an Flow Five 2019 Flow Equation Linearization of Flow Equations. Jamal H. Abou-Kassem, The flow equations presented in Chapter 7 are generally... Linearization of flow equations. Jamal H. Abou-Kassem, The flow equations presented in Chapter 7 are generally... Flow equations using CVFD terminology.. Correction of Bernoulli Equation for Fluid Friction Fluid friction can be defined as any conversion of mechanical energy into heat in a flowing stream. In frictional flow the quantity is not constant along a streamline but always decreases in the direction of flow

- Flow Equation. Flow equations expressed by pressure, pressure square, or pseudo pressure as described earlier can be presented in general forms:(2.60)∇2ϕ=1η·∂ϕ∂t,where the meaning of ϕ is ϕ = p in pressure expression; From: Dynamic Well Testing in Petroleum Exploration and Development, 2013. Related terms: Porous Medium; Hydraulic Conductivit
- Compressible flow equation . Bernoulli developed his principle from his observations on liquids, and his equation is applicable only to incompressible fluids, and steady compressible fluids up to approximately Mach number 0.3. It is possible to use the fundamental principles of physics to develop similar equations applicable to compressible fluids. There are numerous equations, each tailored.
- Viele übersetzte Beispielsätze mit flow equation - Deutsch-Englisch Wörterbuch und Suchmaschine für Millionen von Deutsch-Übersetzungen. flow equation - Deutsch-Übersetzung - Linguee Wörterbuc
- Most common equation used for friction coefficient calculation is Colebrook-White formula and it is used for the turbulent flow in the pressure drop calculator: where is: f - friction factor; Re - Reynolds number; D - internal pipe diameter; k r - pipe roughness
- flow velocity is a solenoidal field, or using another appropriate energy equation respectively (the simplest form for Euler equations being the conservation of the specific entropy). Historically, only the incompressible equations have been derived by Euler. However, fluid dynamics literature often refers to the full set - including the energ
- The DC Power Flow Equations 1.0 Introduction Contingency analysis occurs within the EMS by assessing each possible contingency (usually all N-1) one at a time. That is, we start from a solved power flow case representing current conditions (from the state estimator), then perform contingency assessment as follows: 1. If all contingencies assessed, go to 5
- ing the vascular resistance and hence flow rate of intravenous fluids that may be achieved using various sizes of peripheral and central cannulas. The equation states that flow rate is proportional to the radius to the fourth power, meaning that a small increase in the internal diameter of the cannula yields a significant increase in flow rate of IV fluids. The radius of IV cannulas is typically measured in gauge, which is.

11 We understand the flow of Nothing and, with it, the equations (1) and (2) as fundamental - in the sense that everything existing must be traced back to an alteration of the flow and, therefore, to the equations (1) and (2) Generally speaking, flow equations for flow in porous materials are based on a set of mass, momentum and energy conservation equations, and constitutive equations for the fluids and the porous material involved. For simplicity, we will in the following assume isothermal conditions, so that we not have to involve an energy conservation equation. However, in cases of changing reservoir. Flow equation contains correctly the non-perturbative information ! (essential scaling usually described by vortices) Von Gersdorff Kosterlitz-Thouless phase transition (d=2,N=2) Correct description of phase with Goldstone boson ( infinite correlation length ) for T<Tc. Exact renormalization group equation. wide applications particle physics gauge theories, QCD Reuter Marchesini et al. flow equation die Strömungsgleichung Pl.: die Strömungsgleichungen flow equation [TECH.] die Durchflussgleichung flow der Strom Pl.: die Ströme [fig.] equation [MATH.] die Gleichung Pl.: die Gleichungen equation der Ausgleich Pl. equation die Gleichsetzung Pl.: die Gleichsetzungen equation die Gleichstellung Pl.: die Gleichstellunge The basis of the AGA flow equations is an f value that is a function of Reynolds number. The classic equation for Reynold number is: Re = σ V D /μ (Equation 2

- g a horizontal flow (neglecting the
- STEADY FLOW ENERGY EQUATION. First Law for a Control Volume (VW, S & B: Chapter 6) Frequently (especially for flow processes) it is most useful to express the First Law as a statement about ratesof heat and work, for a control volume.; Conservation of mass (VW, S & B: 6.1). Conservation of Energy (First Law) (VW, S & B: 6.2).
- The equation can be represented as: where Q = flow (cubic metres per second) = coefficient of discharge A = area of orifice (square metres
- A Tutorial on Pipe Flow Equations by Donald W. Schroeder, Jr. Stoner Associates, Inc. P.O. Box 86 Carlisle, Pennsylvania 17013-0086 August 16, 2001 Preface and Dedication This paper is a form of plagiarism for it contains few new thoughts! The author is extremely indebted to the following two groups of engineers for developing its concepts fully

Units in flow rate calculator: You may enter numbers in any units, so long as you are consistent.(L) means that the variable has units of length (e.g. meters). (L 3 /T) means that the variable has units of cubic length per time (e.g. m 3 /s).. Flow rate equation: Q = VA.If circular, then A = π D 2 / 4. The flow rate calculation does not check for unreasonable inputs such as negative values ** Well flow calculations focus essentially on two aspects of fluid flow: pressure profile along the flow path and the rate versus pressure relationship at key points of interest (nodes), as illustrated in Figure 1**. The main parameters of interest (all in units of psia) are pR = reservoir pressure pwf = wellbore (bottomhole) flowing pressur **Equations** used in this Calculator: As long as the fluid speed is sufficiently subsonic (V < mach 0.3), the incompressible Bernoulli's **equation** describes the **flow** reasonably well. Applying this **equation** to a streamline traveling down the axis of the horizontal tube gives, where location 1 is upstream of the orifice, and location 2 is slightly behind the orifice. It is recommended that location.

Venturi Flow Equation and Calculator. A Venturi meter is used to measure the flow rate through a tube or volumetric flow rate, Q. A venturi tube can also be used to mix a liquid with a gas and siphon into the venturi flow. If a pump forces the liquid through a tube connected to a system consisting of a venturi to increase the liquid speed (the diameter decreases), a short piece of tube with a. flow continuity equation. The flow continuity equation : Taking the average speed : Section A x Speed A = Section B x Speed B = constant volume flow. we deduce the velocity at point B. Speed B = Section A / Section B x Speed A. We estimated in formulas continuity flow volume above, the fluid is incompressible Equation for the calculation of fluid (gas, vapor, liquid) flow through conduits or channels; consists of an interrelation of fluid properties (such as density or viscosity), environmental conditions (such as temperature or pressure), and conduit or channel geometry and conditions (such as diameter, cross-sectional shape, or surface roughness) The equation of the flow rate have a further meaning in practice. The flow rate is directly dependent on the viscosity of the fluid. The viscosity of a fluid can therefore be easily determined from the flow rate. A capillary viscometer is based on this principle. Remark. Frequently, reference is made at this point to the example of the narrowing of veins and fine blood vessels, which according.

The most widely used equation for uniform open channel flow* calculations is the Manning equation: Q = (1.49/n)A(Rh 2/3)S1/2 (1) Where: • Q is the volumetric flow rate passing through the channel reach in cfs. • A is the cross-sectional area of flow normal to the flow direction in ft2. Flow separation and reattachment are strongly dependent on a correct prediction of the development of turbulence near walls. ME469B/3/GI 22 Damping Functions Approach (Low-Re k-ε) The equations are integrated to the wall WITHOUT assuming an universal law for the velocity profile and an equilibrium conditions for k and ε The problem is that the model predicts the wrong behavior for k and ε. This article describes a novel isothermal pipe flow equation that better represents the properties of gas flow in a pipe and yields more accurate predictions of mass flux. The article also compares the calculation results of the two isothermal equations (novel versus conventional) using an example piping system. The newly derived, isothermal flow equation presented here is called the novel isothermal pipe flow equation for ideal gases (to differentiate it from the. The equation of continuity states that for an incompressible fluid flowing in a tube of varying cross-section, the mass flow rate is the same everywhere in the tube. The mass flow rate is simply the rate at which mass flows past a given point, so it's the total mass flowing past divided by the time interval. The equation of continuity can be reduced to Since volume flow rate measures the amount of volume that passes through an area per time, the equation for the volume flow rate looks like this: In S.I. units (International System of Units), volume flow rate has units of meters cubed per second, , since it tells you the number of cubic meters of fluid that flow per second

Flow equations for gas and multiphase flow Diffusitivity equation for gas flow. This form of the diffusivity equation is linear, which makes solutions (such as the... Pseudopressure. Other forms of the equation for flow of gases must be developed because the equation of state for a.... Flow Equations Flow Rate (Q) Calculation. A: Area C: Discharge coefficient d: density ( water density = 1000kg/m³ ) D: Diameter g: Gravity 9.8 m/s² K: Flow coefficient (Kv)(Cv) Q: Flow rate SG: Specific gravity (1 for water) v: Flow velocity Δh: Head Drop (high of fluid) ΔP: Pressure Drop . Q = C · SQRT ( 2 · g · Δh) · A : Q = C · SQRT ( 2 · g · Δh) · ( D)² · π / 4 : Q = C.

Flow equations for Hamiltonians. Ann. Physik, Leipzig 3, 77 (1994) Flow-equations are introduced in order to bring Hamiltonians closer to diagonalization. It is characteristic for these equations that matrix-elements between degenerate or almost degenerate states do not decay or decay very slowly. In order to understand different types of physical systems in this framework it is probably. Solution of the equations for unconfined groundwater flow is complicated by the fact that the aquifer thickness changes as groundwater is withdrawn; i.e., removal of water from the aquifer lowers the water table. If vertical components of flow are negligible or small, we can use the Dupuit assumptions to simplify the solution of the equations. These assumptions are: 1. assume that the flow is.

Two-dimensional flow equation Suppose a confined aquifer having a constant thickness (b). We can analyze the mass balance of a box in this aquifer in a way similar to the analysis of one-dimensional flow. We saw that Min-Mout in x-direction is given by (see p.6-1): Similarly, Min-Mout in y-direction is given by: [] ∂ ∂ ∂ ∂ = ∆ Summary: Bernoulli equation for ideal flow. Steady rotational or irrotational flow along streamline. Unsteady or steady irrotational flow everywhere in the fluid. For hydrostatics,. hydrostatic pressure (Archimedes' principle) Steady and no gravity effect () Venturi pressure (created by velocity).

Equations used in this Calculator: As long as the fluid speed is sufficiently subsonic (V < mach 0.3), the incompressible Bernoulli's equation describes the flow reasonably well. Applying this equation to a streamline traveling down the axis of the horizontal tube gives, where location 1 is upstream of the orifice, and location 2 is slightly behind the orifice. It is recommended that location. This equation is known as the Buckley-Leverett equation above, after the famous paper by Buckley and Leverett1 in 1942. Derivation of the frontal advance equation Since S w (x,t) we can write the following expression for saturation change w dS w= ∂S ∂x dx+ ∂S w ∂t dt In the Buckley-Leverett solution, we follow a fluid front of constant saturation during the displacement process; thus. Swamee (1992) and Swamee et al. (2000) provided an **equation** for determining the discharge coefficient for free **flow** based on the dimensionless variable y=a and for submerged **flow** based on the.

Hazen-Williams equation. The Hazen-Williams equation is an empirically derived formula that describes the velocity of water in a gravity flow. Remember that the Hazen-Williams equation is valid only for water - applying it for any other fluid will give you inaccurate results. It also doesn't take into account the temperature of the water, and is only accurate for the 40-75 °F (4-25 °C) range * These equations are at the heart of fluid flow modeling*. Solving them, for a particular set of boundary conditions (such as inlets, outlets, and walls), predicts the fluid velocity and its pressure in a given geometry. Because of their complexity, these equations only admit a limited number of analytical solutions. It is relatively easy, for instance, to solve these equations for a flow. 3. Equation of state Although the Navier-Stokes equations are considered the appropriate conceptual model for fluid flows they contain 3 major approximations: Simplified conceptual models can be derived introducing additional assumptions: incompressible flow Conservation of mass (continuity) Conservation of momentum Difficulties Fluid dynamics offers a systematic structure—which underlies these practical disciplines—that embraces empirical and semi-empirical laws derived from flow measurement and used to solve practical problems. The solution to a fluid dynamics problem typically involves the calculation of various properties of the fluid, such as flow velocity, pressure, density, and temperature, as functions of. The mass flow equation is quite messy, so here is a JavaScript calculator that solves the mass flow equation for you for both the mass flow rate and the weight flow rate: Mass Flow Calculator. Units: Mach Gamma p total T total Area. Compute. Input. Output. Mass Flow Rate . Weight Flow Rate. To change input values, click on the input box (black on white), backspace over the input value, type.

The steady flow requirement is usually not too hard to achieve for situations typically analyzed by the Bernoulli equation. Steady flow means that the flowrate (i.e. discharge) does not vary with time. The inviscid fluid requirement implies that the fluid has no viscosity. All fluids have viscosity; however, viscous effects are minimized if travel distances are small. To aid in applying the. 1.5 Flow Equations in Cartesian and Cylindrical Coordinate Systems Conservation of mass, momentum and energy given in equations (1.1), (1.5) and (1.12) (or alternatively given in (1.16), (1.18) and (1.19) for incompressible flows) are valid for any coordinate system. In order to write them for a specific coordinate system first we need to define the velocity vector components in these systems. Laminar flow strictly means that there is no fluctuation of velocity. For the fluctuations we use RANS modeling, and for closer of that equation we use turbulence models. If there wont be any. There are several equations and tables for determining the flow in natural gas pipes and the pressure drops associated with those flows, or vise versa. The purpose of this article is to evaluate the available low pressure natural gas flow equations among themselves and with the tables in the codes. Previous articles in this series were used to evaluate various equations used for determining.

COMPRESSIBLE FLOW 283 Example 17.1 [Sound speed in the atmosphere]: For dry air at 20 C with D7=5and Mmol D29g mol1, the sound speed comes to c0 D343m s1 D1235km h1. Since the temperature of the homentropic atmosphere falls linearly with height according to eq. (2.49) on page 36, the speed of sound varies with height zabove the ground as cDc0 r 1 z h2; (17.8) where c0is the sound speed at sea. ** Equation (3) is used for designing head flow meters for specific plant operating conditions**. When the process is operating, the meter parameters are fixed, and the pressure difference is measured. Then, the flow can be calculated from the meter equation, using the appropriate values for C meter and Y. All constants are combined, leading to the following relationship. relationship for installed. The Manning equation can be used for uniform flow in a pipe, but the Manning roughness coefficient needs to be considered to be variable, dependent upon the depth of flow. This course includes a review of the Manning equation, along with presentation of equations for calculating the cross-sectional area, wetted perimeter, and hydraulic radius for flow of a specified depth in a pipe of known. An equation for the fluctuation (which might be an imposed disturbance) can be obtained by subtracting the equation for the mean (or base) flow from that for the instantaneous motion. We already did this for the continuity equation. Now we will do it for the momentum equation. Subtracting equation 13 from equation 12 yields an equation for the fluctuation as

The application of steady flow energy equation can be used to study the performance of many engineering devices that undergo thermodynamic processes, as these devices closely satisfy the conditions for steady flow processes. For example, the engineering devises like boiler, turbine, condenser/heat exchanger, feed water pump, cooling tower, and stack of steam power plant (Fig. 11.1) run nonstop. Chapter 3 Bernoulli Equation 3.1 Flow Patterns: Streamlines, Pathlines, Streaklines 1) A streamline , is a line that is everywhere tangent to the velocity vector at a given instant. Examples of streamlines around an airfoil (left) and a car (right) 2) A . pathline. is the actual path traveled by a given fluid particle. An illustration of pathline (left) and an example of. The Power Flow Equations 1.0 The Admittance Matrix Current injections at a bus are analogous to power injections. The student may have already been introduced to them in the form of current sources at a node. Current injections may be either positive (into the bus) or negative (out of the bus). Unlike current flowing through a branch (and thus is a branch quantity), a current injection is a. FLOW LINES (Streamlines) Author: Dr. Parvini Determining the flow lines (also known as field lines, streamlines, integral curves) of a vector field usually amounts to solving a differential equation or a system of differential equations flow equationの意味や使い方 流動方程式; 流れ方程式 - 約1173万語ある英和辞典・和英辞典。発音・イディオムも分かる英語辞書

- SFEE (Steady Flow Energy Equation) is an equation that describes the total engergy flows of an open system. It is assumed that the mass flow through the system is constant (this is why it is called 'Steady Flow Energy'). The SFEE is used to analyze a fluid flow across a piping system with the consideration of losses. Unlike Bernoulli's equation Pump and turbine can be involved in SFEE, which.
- imal total.
- Flow Equations for sluice gate.Introduces different flow equations to students which are widely utilized for the design of sluice gates connected to open channel.This tutorial will help to understand and articulate the basic flow equation utilized by designers all over the world
- Water flow rate calculations for uniform open channel flow are typically made with the Manning equation. The Manning equation gives an empirical relationship among the open channel water flow rate; the channel slope, hydraulic radius and Manning roughness coefficient; and the cross-sectional area of flow. The Manning equation is given for U.S. units and for S.I. units
- The flow equations, however, can be troublesome to work with as the flow is governed by three separate flow regimes: low, transitional, and main. For typical applications, the need to transition from one equation to another as the level in the flume rises and falls becomes needlessly cumbersome. To simplify flow calculations, Bos developed a single, standard, best-fit equation for the data.

* Partially Full Pipe Flow Calculator - This engineering calculator determines the Flow within a partially full pipe using the Manning equation*. This calculator can also be used for uniform flow in a pipe, but the Manning roughness coefficient needs to be considered to be variable, dependent upon the depth of flow steady flow process and also we have seen First law of thermodynamics for a closed system undergoing in a cycle in our recent post. Today we will see here the steady flow energy equation for turbine and compressor with the help of this post Flow in Pipes Running Full. The Colebrook White equation calculates the velocity ( v) of flow through a circular pipe running full using the below equation; This is the acceleration due to gravity, typically taken as 9.81m/s 2 at sea level. This is the internal diameter of the pipe being considered. This is effectively the slope of pipe in m/m Bernoulli's equation along the streamline that begins far upstream of the tube and comes to rest in the mouth of the Pitot tube shows the Pitot tube measures the stagnation pressure in the flow. Therefore, to find the velocity V_e, we need to know the density of air, and the pressure difference (p_0 - p_e). The density can be found from standard tables if the temperature and the pressure are.

- mass flow rate through a tube is a constant and equal to the product of the density ρ, velocity V, and flow area A: m = ρ * V * A (6) Considering the mass flow rate m equation, it appears that for a given area A and a fixed density , we could increase the mass flow rate indefinitely by simply increasing the velocity v. In real fluids, however.
- The 1-D Heat Equation 18.303 Linear Partial Diﬀerential Equations Matthew J. Hancock Fall 2006 1 The 1-D Heat Equation 1.1 Physical derivation Reference: Guenther & Lee §1.3-1.4, Myint-U & Debnath §2.1 and §2.5 [Sept. 8, 2006] In a metal rod with non-uniform temperature, heat (thermal energy) is transferred from regions of higher temperature to regions of lower temperature. Three physical.
- ing two-dimensional flow of soil elements. Consider a soil element of infinitesimally small size of dx and dz in X- and Z-directions, respectively, through which the flow is taking place, shown in Fig. 10.8. Consider unit length of the soil element in the Y-direction. Let v x be the velocity of flow at the entry in the X.
- Considering the mass flow rate equation, it appears that for a given area, we can increase the mass flow rate to any desired point by increasing the velocity. However, in real fluids, compressibility effects limit the speed at which a flow can be forced through a given area. Mass Flow Rate for an Ideal Compressible Gas . For a compressible, ideal gas, the mass flow rate is a unique function of.
- Any equation computing flow in standard units must predict the effective expansion of the gas as if it were to transition from flowing conditions (the actual pressure and temperature it experiences flowing through the pipe or pipeline) to standard conditions (1 atmosphere, 60 degrees Fahrenheit)

When applied to particles on a single streamline in steady flow, Equations 9 and 10 are both known as the Bernoulli equation, and the corresponding, constant value of E/tot V or E/tot mg is referred to as the Bernoulli constant. Note that the Bernoulli equation can be used without any knowledge about the detailed path that the fluid particle follows as it travels from point 1 to point 2; all. If the flow can be assumed irrotational, then the problem reduces to a solution of Laplace's equation, and powerful potential flow methods can be used. In fact, for potential flow, it is possible to show that the flow is entirely determined by the normal velocity at the surface. And this is, of course, the source of our problem. There is no role left for the viscous no-slip boundary. Flow Through a Throttle Body A Comparative Study of Heat Transfer, Wall Surface Roughness and Discharge Coeﬃcient LIU-IEI-TEK-A-07/0071-SE Per Carlsson, Linköpin Reynolds Equation (Liquid or Gas Flow) Eigenfrequency: Frequency Domain: Stationary: Time Dependent: Thin-Film Flow, Shell, 3D: Modified Reynolds Equation (Gas and Rarefied Gas Flow) Eigenfrequency: Frequency Domain: Stationary: Time Dependent: Reynolds Equation (Liquid or Gas Flow) Eigenfrequency: Frequency Domain: Stationary : Time Dependent: Boundary Conditions : Atmosphere/Gauge: Boundary. Viele übersetzte Beispielsätze mit flow rate - Deutsch-Englisch Wörterbuch und Suchmaschine für Millionen von Deutsch-Übersetzungen

Flow Equations Dimensional Flow Coefficient (Cv and Kv) Calculation. A: Area C: Discharge coefficient d: density ( water density = 1000kg/m³ ) D: Diameter g: Gravity 9.8 m/s² K: Flow coefficient (Kv)(Cv) Q: Flow rate SG: Specific gravity (1 for water) v: Flow velocity Δh: Head Drop (high of fluid) ΔP: Pressure Drop . K = Q / sqrt(ΔP / SG) K = Cv, when K is referenced in [gpm] [psi] units. Continuity equation. Fluid flow through a volume can be described mathematically by the continuity equation. The continuity equation has many uses, and its derivation is provided to illustrate the construction of a partial differential equation from physical reasoning. We begin by considering the flow illustrated in Fig. 1.The block in Fig. 1 has length (Δx), width (Δy), and depth (Δz) Manning's equation has been the most successful of all open-channel empirical equations, based on the resistance to flow and derived from observation. In fact, it is no exaggeration to say it is. The general form of gradually varied flow(GVF) equation is: (dy/dx)=(So-Sf)/(1-Fr^2) In this equation, So = Bottom slope, positive in the downward direction. Sf = Friction slope. It is positive in the downward direction. y = Water depth, measured from culvert bottom to water surface. x = Longitudinal distance, measured along the culvert bottom . Fr = Froude number. The friction slope is. Equations of Incompressible Fluid Flow In most situations of general interest, the flow of a conventional liquid, such as water, is incompressible to a high degree of accuracy. A fluid is said to be incompressible when the mass density of a co-moving volume element does not change appreciably as the element moves through regions of varying pressure. In other words, for an incompressible fluid.

The general equation for mass flow rate measurement used by ISO5167 standard is: 1 2 4 1 2 1 4 ρ π ε β ⋅⋅⋅ ⋅ ⋅∆⋅ − = d p C QM You will find it on section 5.1 of ref-1, this formula is obtained in part from additional complex theoric analysis but comes mostly from experimental research done along years and presented in several publications. What is interesting about ISO5167. Chapter 8 Laminar Flows with Dependence on One Dimension Couette flow Planar Couette flow Cylindrical Couette flow Planer rotational Couette flow Hele-Shaw flow Poiseuille flow Friction factor and Reynolds number Non-Newtonian fluids Steady film flow down inclined plane Unsteady viscous flow Suddenly accelerated plate Developing Couette flow Reading Assignment: Chapter 2 of BSL, Transport. Substitute in the power flow equations and determine the deviations from the solution. 4. Update the estimated voltages based on some commonly known numerical algorithms (e.g., Newton-Raphson or Gauss-Seidel). 5. Repeat the above process until the deviations from the solution are minimal. Example Consider a 4-bus power system below. Assume that -bus 1 is the slack bus and that it has a. The flow rate measurement in a rectangular weir is based on the Bernoulli Equation principles and can be expressed as: q = 2/3 cd b (2 g)1/2 h3/2 (1) where. q = flow rate (m3/s) h = elevation head on the weir (m) b = width of the weir (m) g = 9.81 (m/s2) - gravity. cd = discharge constant for the weir - must be determined Erstellen Sie einfach automatisierte Workflows mit Microsoft Power Automate (ehemals Microsoft Flow), um die Produktivität durch die Automatisierung von Geschäftsprozessen zu verbessern DESIGN EQUATIONS. The following section will detail simplified equations for the design of small liquid-fuel rocket motors. The nomenclature for the motor design is shown in Figure 6. Figure 6 Motor Design Configuration Nozzle. The nozzle throat cross-sectional area may be computed if the total propellant flow rate is known and the propellants and operating conditions have been chosen.