Burning Rate Analysis

D, W. Blair, CombustFlame 20 (1), 105—9 (1973) CA 78, 113515 (1973) A simple heat-transfer model is coupled with an Arrhenius-type pyrolysis law to study the effect of solid-state heat-transfer losses on burning rates of solid rocket-proplnt strands. Such heat-transfer losses materially affect the burning rates and also cause extinction phenomena similar to some that had been observed exptly. Strand diam and compn, adiabatic burning rate, and the heat-transfer film coeff at the strand surface are important variables. Results of theoretical analysis are applied to AP-based composite solid proplnts... 

Theoretical Analysis of Resonance Tube , The Singer Company, Final Report KD 72-82 (1972) 58) F.J. Valenta, The State of the Art of Navy Pyrotechnic Delays , Expls Pyrots (The Franklin Institute Research Laboratories) 5, Nos 11 12 (Nov-Dec 1972). See also Ref 144, pp 185—95. See also Some Factors Affecting Burning Rates and Variability of Tungsten and Manganese Delay Compositions , Ref 144, pp 157—83. See also Mil Spec for Tungsten Delay Compositions , MIL-T-23132A (June 1972) 59) C.F. Parrish et al, Radiation... 

In making a preliminary comparison between predicted and measured burning rates, Nachbar has shown that the present analysis does not predict the observed effect of pressure on the burning rate. In fact, the model predicts... 

Friedly (F4) expanded the theoretical analysis of Hart and McClure and included second-order perturbation terms. His analysis shows that the linear response of the combustion zone (i.e., the acoustic admittance) is not sign-ficantly altered by the incorporation of second-order perturbation terms. However, the second-order perturbation terms predict changes in the propellant burning rate (i.e., transition from the linear to nonlinear behavior) consistent with experimental observation. The analysis including second-order terms also shows that second-harmonic frequency oscillations of the combustion chamber can become important. 

The constant 3 is an order of magnitude estimate which depends on the approximate analysis for the model of Figure (4.10). In addition, the burning rate m " and the properties a and cp should be evaluated at some appropriate mean temperature. For example, in Equation (4.34), the more correct expression for is... 

The asymptotic burning rate behavior under saturated flame radiation conditions is a useful fact. It provides an upper limit, at pool-like fuel configurations of typically 1-2 m diameter, for the burning flux. Experimental values exist in the burning literature for liquids as well as solids. They should be thoughtfully used for design and analysis purposes. Some maximum values are listed in Table 9.3. 

For a standard business card, in the vertical length dimension, determine the steady burning rate (g/s) for one side of the card saturated with ethanol. Only the ethanol bums. Show your analysis and all assumptions. This is a calculation, not an experimental determination, though experiments can be conducted. State all data and sources used. You will have to make approximations and estimates for quantities in your analysis. 

A seemingly simple measurement method to quantify the burning rate (conversion gas rate) of a simulated crosscurrent moving bed was obtained by Lamb et al. However, the mathematical relationship between burning rate and measurands was not explicitly declared. No verification method is used and no uncertainty analysis is carried out. The method is badly defined. Consequently, the results would be difficult to reproduce. 

The temperature profile in the combustion wave of a double-base propellant is altered when the initial propellant temperature Tq is increased to Tq -i- ATq, as shown in Fig. 6.15. The burning surface temperature is increased to -i- AT, and the temperatures of the succeeding gas-phase zones are likewise increased, that of the dark zone from Tgto Tg-t- ATg, and the final flame temperature from 7 to Tf-t- ATf If the burning pressure is low, below about 1 MPa, no luminous flame is formed above the dark zone. The final flame temperature is Tg at low pressures. The burning rate is determined by the heat flux transferred back from the fizz zone to the burning surface and the heat flux produced at the burning surface. The analysis of the temperature sensihvity of double-base propellants described in Section 3.5.4 applies here. 

The relationship between temperature sensitivity and burning rate is shown in Fig. 7.21 as a function of AP particle size and burning rate catalyst (BEFP).li31 The temperature sensitivity decreases when the burning rate is increased, either by the addition of fine AP particles or by the addition of BEFP. The results of the temperature sensitivity analysis shown in Fig. 7.22 indicate that the temperature sensitivity of the condensed phase, W, defined in Eq. (3.80), is higher than that of the gas phase, 5), defined in Eq. (3.79). In addition, 4> becomes very small when the propel-... 

EFFECT OF GAS TEMPERATURE ON BURNING RATE. It has been common practice in certain industrial applications to preheat the air before it enters the combustion region. The theoretical analysis of the droplet combustion process indicates that such an increased air temperature does not change materially the mass burning rate,... 

Among the several theoretical analyses of the combustion of a single droplet, the classical derivation was presented by Godsave (24), whose analysis predicted that the mass burning rate should vary directly as the product of flame and droplet radii and... 

Two-way analysis of variance (and higher classifications) leads to the presence of interactions. If, for example, an additive A is added to a lube oil stock to improve its resistance to oxidation and another additive, B, is added to inhibit corrosion by the stock under load or stress, it is entirely possible that the performance of the lube oil in a standard ball-and-socket wear test will be different from that expected if only one additive has present. In other words, the presence of one additive may adversely or helpfully affect the action of the other additive in modifying the properties of the lube oil. The same phenomenon is clearly evident in a composite rocket propellant where the catalyst effect on burning rate of the propellant drastically depends on the influence of fine oxidizer particles. These are termed antagonistic and synergistic effects, respectively. It is important to consider the presence of such interactions in any treatment of multiply classified data. To do this, the two-way analysis of variance table is set up as shown in Table 1.24. 

---