Performance parameter

The parameters most commonly used to evaluate the performance of rocket engines are introduced first. From these, the significant parameters which determine the performance of propellants are derived. Similar to the approach in (15) simplified expressions will be derived theoretically in terms of the thermodynamic and other properties of the system in order to give insight into the fundamental significance of the individual performance parameters. These simplified expressions are derived from the so-called ideal rocket motor analysis. More accurate derivations are deferred until the next sections where the appropriate aspects of chemical thermodynamics are developed. 

The performance analysis of a rocket motor comprises the calculation of  

Several terminologies are used in the chemical reaction engineering literature to represent the performance of both catalytic and noncatalytic chemical processes. 

The definitions that are commonly used are given as follows  

Conversion It indicates the progress of the reaction and is defined as the ratio of the amount of the limiting reactant transformed and the total amount fed to the reactor. For the following parallel reactions 

Yield It is the amount of product formed in the reaction referred to the amount of the reactant fed to the reactor. Considering the reactions indicated in Equation 2.34 the yield of A3 with respect to reactant Aj is defined as  

Selectivity The selectivity corresponds to the amount of the desired product formed with respect to the amount of the compound reacted  

there must be some way of measuring the performance of a design. Consider the following performance parameters  

Relative depth Qi) or diameter (d) of a section for equal strength 

Accuracy of mass measurement Accurate mass measurements  

Difference between calculated (exact) and experimentally determined (accurate) masses  

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Accuracies of the flow meters discussed herein are specified as either a percentage of the full-scale flow or as a percentage of the actual flow rate. It may be convenient in some appHcations to compare the potential inaccuracies in actual volumetric flow rates. For example, in reading two Hters per minute (LPM) on a flow meter rated for five LPM, the maximum error for a 1% of full-scale accuracy specification would be 0.01 x 5 = 0.05 LPM. If another flow meter of similar range, but having 1% of actual flow rate specification, were used, the maximum error would be 0.01 x 2 = 0.02 LPM. To minimize errors, meters having full-scale accuracy specifications are normally not used at the lower end of their range. Whenever possible, performance parameters should be assessed for the expected installation conditions, not the reference conditions that are the basis of nominal product performance specifications. 

Table 1. Comparison of Electrooptic Modulator Performance Parameters of NLO Materials ...

Tire compounders generally use two basic approaches to formulate for achieving desired tire performance the use of known relationships of a given compound to a specific performance parameter, and estabUshing the relationships of physical properties to a given performance parameter. 

Using physical properties relating to performance parameters leads to the development of algorithms for predicting performance for laboratory screening of potential improvements. Many of these algorithms have been estabUshed. The two main categories of measurement criteria are quasi static and dynamic mechanical properties. 

Dynamic properties are measured by continuous cycles of varying deformation (strain) and/or stress (force required to secure a given strain), at varying frequencies which can be set close to those a component would experience in a tire. These properties are more correlative to many tire performance parameters. 

By far the best application of computers to evaporators is for working up operators data into the basic performance parameters such as heat-transfer coefficients, steam economy, and dilution. 

Since aerothermal performance of compressors and turbines is very sensitive to inlet temperature and pressure variations, it is essential to normalize the aerothermal performance parameters such as flow, speed, horsepower, etc., to standard-day conditions. When these corrections to standard conditions are not applied, a performance degradation may appear to occur when in fact it was a performance change resulting merely from ambient pressure and temperature changes. Some of the equations for obtaining correction to standard-day conditions are given in Table 19-3. 

The equations and performance parameters for all the major components of a power train must be corrected for ambient conditions and certain parameters must be further corrected to design conditions to accurately compute the degradation. Therefore, to fully compute the performance, and degradation of the plant and all its components, the actual, corrected, and transposed to reference conditions of critical parameters must be computed. 

Table 7. The major performance parameters of a typical AGR (Heysham II and Tomess design) [33]...

The HTGR designed by the General Atomic Company and constructed at Peach Bottom, Pennsylvania, U.S.A., was a 40 MW(e) experimental power plant which was similar in many respects to the Dragon reactor. Peach Bottom started commercial operation on June 1, 1967, and ceased operation on October 31, 1974 [36]. The major performance parameters of the Peach Bottom Reactor are shown in Table 8. 

Pressure loss through the cyclone is also a key performance parameter, and this depends mainly on the design of the cyclone. In general, the pressure drop across the cyclone collector is small compared with most other dust collectors, but the higher the collection efficiency required, the larger the pressure drop and hence the energy consumption required. 

In general, a gas turbine CHP plant may not exaetly mateh the eleetrieity and heat demands. A plant with a recuperator may meet the heat load (Qu)cg = but not the power load (Wgg < Wd= 1) so extra power from the grid is required (Wc) as illustrated in Fig. 9.4. Following a procedure similar to that given in Section 9.2.3 it may be shown [ 1 ] that the performance parameters for the total plant are then... 

The major performance parameters at design operating conditions are as follows ... 

A area ratio in heat transfer also CO2 performance parameter (-), kg/kWh... 

Define maintenance instructions stating the performance parameters to be maintained, the frequency of maintenance, how it is to be conducted, the action to be taken in the event of failure, the procedures to be followed in carrying out repairs, and the training required of those performing the maintenance tasks. 

Several techniques are available in the literature for evaluation of the flame temperature, exit temperature, equilibrium composition of combustion products, and performance parameters of energetic composites [11-13]. The optimum combination of the composite ingredients is determined by thermodynamic means, so as to arrive at a composition having maximum performance... 

Kessler and Wankat [101] have examined several column performance parameters, and for O Connell s [49] data presented in Figure 8-29 they propose equations that reportedly fit the data generally within about 10% limits ... 

Davis, H., Equivalent Performance Parameters for Turboblowers and Compressors, Paper No. 56-A-122, ASME, presented at New York meeting (1956). 

If the above performance parameters for a turbine motor design are known for a given circulation flowrate and mud weight (denoted as 1), the performance parameters for the new circulation flowrate and mud weight (denoted as 2) can be found by the following relationships ... 

It should be noted that the positive displacement motor performance parameters are independent of the drilling mud weight. Thus, these performance parameters will vary with motor design values and the circulation flowrate. 

Listed below in tabular form are the available parameters found for over 43 selected PBX formulations, supported by unclassified refs. Table 3 presents the nomenclature and formulation of each compn Table 4, sensitivity and stability data and Table 5, performance parameters... 

R.C. Oliver et al, USDeptCom, Office Tech-Serv ..AD 265822,(1961) CA 60, 10466 (1969) Metal additives for solid proplnts formulas for calculating specific impulse and other proplnt performance parameters are given. A mathematical treatment of the free-energy minimization procedure for equilibrium compn calcns is provided. The treatment is extended to include ionized species and mixing of condensed phases. Sources and techniques for thermodynamic-property calcns are also discussed... 

One of the most important phenomena in material science is the reinforcement of mbber by rigid entities, such as carbon black, clays, silicates, calcium carbonate, zinc oxide, MH, and metal oxide [45 7]. Thus, these fillers or reinforcement aids are added to mbber formulations to optimize properties that meet a given service application or sets of performance parameters [48-53]. Although the original purpose is to lower the cost of the molding compounds, prime importance is now attached to the selective active fillers and their quantity that produce specific improvements in mbber physical properties. 

Widely used parameters are the specific energy or power per unit mass (w = W/M, in Wh/kg, orp = P/M, in W/kg). In each battery type the specific energy is a falling function of specific power. Plots of w vs. p (Ragone, 1968) yield a clear illustration of the electrical performance parameters of given types of batteries and are very convenient for their comparison (see Fig. 19.4). 

From the 1960s onward, alkaline zinc-manganese dioxide batteries started to be produced. They have appreciably better electrical performance parameters (see Section 19.4.3) but do not differ from Leclanche batteries in their operating features, are produced in identical sizes, and can be used interchangeably with them. Thus, a gradual changeover occurred and phaseout of the older system is now almost complete. 

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